Intersect errors, memory issues in QGIS

my datasets are:               Track_02(simple road polyline shp)     ***intersected with***     road_cat_cls(polygon for road categorization)     elev_rcls_poly(polygonized classified DEM)     slp_rcls_poly(polygonized classified slope grid)      With Arc, you are able to intersect multiple layers, however in QGIS it is limited to 2 at a time? Also, the more intersects I run (I intersect the previous output with the next polygon layer in line) it takes longer and longer obviously, and when I get to the last, slp_rcls_poly, it is sticking on 4%. Lastly, after checking the second output, I am seeing that the intersect has not fully worked, as part of my road is missing from that output. Any help greatly appreciated.


how feasible is building my own map server? providing GeoCoding, Directions and Navigation

My need is a **heavy** use of routing. same as Google's Directions API. I'm looking for a viable alternative to abusing google and paying them too much. how difficult is it to have my own server for that task?


How to construct a gs:PointStacker parameters using openlayers against geoserver

I want use openlayers 2.13 dev and geoserver to achive the cluster of points. I user openlayers 2.13 dev 's "OpenLayers.WPSClient". here is my code:               <!DOCTYPE html>               <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">     <meta name="apple-mobile-web-app-capable" content="yes">     <title>wps</title>      <link rel="stylesheet" type="text/css" href="./theme/default/style.css">     <link rel="stylesheet" type="text/css" href="style.css" >                                 <button onclick="cluster();">cluster</button>

                but I don't know how to construct the **pointStacker.execute** especially **outputBBOX** , chrome gives me the error `Uncaught TypeError: Cannot read property 'left' of undefined`, meaning the source code's `options.bounds.left` could somebody give some help!


QGIS line style

I found the latest QGIS has a great tool to create complex styles, however looks like one small but very useful thing is missing, or I can't find it. I'm trying to create a line style something like "- x - x -". I can do it in various ways, but none of them gives right results. The problem is that I need to set starting point (shift) either for "-" or "x", so to draw it not from 0. If I set X coordinate shift for the marker it works ok, except line bends, where marker can go outside the line (vertex). **QGIS style:** ![QGIS style](http://i.stack.imgur.com/Erso5.png) **ArcMap style:** ![ArcMap style](http://i.stack.imgur.com/2g1Oi.png) Is there is something to do with it?


Differentially correct GPX file

Is there any way to differentially correct a GPX file using free or open- source tools? Does a GPX file contain the necessary information for differential correction (I can put the timestamp in it accurate to 1s)? As an aside, do I need to disable WAAS on my receiver for this to work?


Global Basin Delineation Across Dateline

I'm trying to delineate all river basins on a global 1/16 degree grid. The algorithm that the Basin tool in the Spatial Analyst Toolbox works well (fast) except it doesn't know how to handle the International Dateline (-180/180 degree line). See example image below... It is important that I process the entire globe at once because I need each basin to have a unique identifier. Can anyone suggest a way of doing this? I'd be open to modifying the Basin tool script if necessary and if I can get my hands on it. I'm using ArcInfo 10.0 and all standard python tools. ![Arctic Basins showing break at International Dateline](http://i.stack.imgur.com/eC6vZ.png)


Produce raster map using universal kriging as interpolation method

I want to do kriging with external drift(universal kriging) in R. The covariate I use is in WGS84 refrence system. Because of nature of kriging which calculates distance in planar surface I have to do transformation from WGS84 to ETRS89. what I want out of kriging is a raster map. Because of the reference system transformation the prediction points are not regular grids and what I get as a result is a vector map. ![Air pollution map using covariate on irregular gird ](http://i.stack.imgur.com/H0OUn.png) I used 'gstat' package in and `spplot()` function to create plots. But When grids are regular (wich I can not define because of nature of the covariate data) with equal distance I have a raster map.


bulk save mapinfo tab files with new projection

Is there a way to builk convert mapinfo files to a new projection (and output in the same mapinfo format) without using the mapinfo sdk? I did look into ogr2ogr but I couldn't get it to work even when I added the to/from epsgs that I needed to the csv files I need to convert from EGSP 28356 -> EPSG 3857


Is it possible to create Domains for an Oracle (non SDE) database?

I have a simple Oracle database (non SDE/Geodatabase) but I want to constrain the values that can be entered into a particular field (ex: the state names that can be stored/entered in a "State" field) This is exactly what Domains are, in an ESRI geodatabase. Does something like this exist outside of Geodatabases? If so, how can I do it?


Openstreetmap - retrieve nearby big cities for a given location

I was wondering how I can retrieve places near a given location? For example, if I pass the osm API the location "Paris" is it possible to retrieve all the main biggest cities around Paris within a given distance? (For example: "osm give me please all the biggest cities near Paris, in a range of 50 kilometers"). Is it possible? Any idea? thanks.


Large survey on unconnected underground networks

We (read I) are currently surveying all the stormwater pits and pipes in our shire, and have run into a few issue with handling unknown network connections. The problem is that a lot of our network is not pit-to-pit like any good network should be (I can thank lack of standards for that) so we have a lot of pits that have a pipe running out to another pipe somewhere underground and it’s just busted in with no junction pit. We are able to get a invert on the outgoing pipe from the pit but not where it joins the main pipe, because well, we don’t know where that main pipe is or even how deep it is. I think a picture will help with what I am describing: ![enter image description here](http://i.stack.imgur.com/Swmpf.png) So the green dot is the new surveyed pit and the X is the invert position. We have a rough direction for the outgoing pipe but no idea how far back into the footpath the main pipe is, so creating a connected network is bloody hard. Now imagine over half your network is like this, and this is an easy case. How do you handle it? I’m interested to know how other people would/have handled doing a full survey of their stormwater (or any other underground) network. Our ultimate goal is to have a complete connected network with inverts at all joins in order to be able to run models. Any help or people to contact would be of great help. I'm very interested to know how you would get inverts for the pipes that have no junction that comes to the surface. Is digging each junction up the only option?


How can I turn a vector layer into a graph G = (V, E)?

I have a number of rail networks, in the form of shapefiles of the "line" type. I want to turn them into a more abstract graph format, i.e. the kind with vertices and edges, not chart-type graphs. Moreover I want these data to be usable outside my GIS programs, in Python. Basically what I want is to extract something along the lines of the TSPLIB format, except with only vertices and edges. For my immediate purposes, I don't even need weights or anything. Just the topology. Is there any relatively pain-free way to do this in QGIS or GRASS? I haven't quite lucked out yet.


How to work with GDAL/OGR in Tomcat?

I make web application in Eclipse using GDAL. In Eclipse in Debug Configurations i add variable path=path/to/gdal/folder. In project i add `gdal.jar` to build path and copy gdal folder in lib directory. And all works fine. After i export my application to WAR file and want to deploy it in another computer. I download gdal for Win 64bit, put it in tomcat/shared/lib and add it in Win varible PATH.   And get error:               java.lang.UnsatisfiedLinkError: org.gdal.ogr.ogrJNI.GetDriverCount()I     org.gdal.ogr.ogrJNI.GetDriverCount(Native Method)      What i can do wrong? **UPDATE** In `catalina.bat` i set `set JAVA_OPTS="-Djava.library.path=/tomcat/shared/lib"` but its not help me. There i get answer that if i see something like this in errors its mean that library is loaded and problem in library itself.


vehicle tracking system in postgresql performance

I am developing the vehicle tracking system using postgresql. When the data comes from device to my DB server, I am calling the following functions after inserting data into log table.   1. Distance Update -- picking up the last inserted row (latitude, longitude) of the specific device from log table and calculating distance with newly inserted row... updating the distance in the same table   2. Trip function -- gets the list of all locations'(stations) latitude, longitude, radius and again calculating the distance [by using this I am able to get the details of trip start date and trip end date and inserting those details into anotehr table]   3. Geofence functions   4. Overspeed function   5. some other functions I will get almost 2000 rows per minute. Will this hit my performance ... otherwise do I need to write the trigger for this... What happens if the data increases in the table more than 10,00,000... because we are picking the last inserted data based on the device everytime? Do i get any db schema for basic vehicle tracking? Thanks in advance, AJ


How to find out which ArcSOM each ArcSOC belongs to?

We have 5 ArcGIS Servers and 1 Web Server. based on the system design proposed by the company the ArcSOM will be installed on the WebServer, and the Other 5 server will host only ArcSOC. how to find out each ArcSOC to which ArcSOM belongs. I monitor all process on all machines, and I found that ArcSOM is installed on all machines, but I am not sure during how the post installation configured and if the ArcSOC's belongs to one ArcSOM.


Following previous instructions to set up adding ecw files to QGIS does not work

I have followed the solutions to setting up ECW in QGIS. However, none of them work. In addition I get a mount - access denied error when trying to load the gdal- ecw and gdal-mrsid plug-ins using the OSGeo4W installer in advanced mode. Any workarounds for this?


How to extract high frequencies from a point shapefile?

I need to get the average of the 3 highest frequencies in a table and append it to a shape file i already have hope you can help me


Open-source GIS implementation of the Huff model

This might be a stretch, but I was wondering if anyone implemented gravity modeling tools or scripts for Retail Market Analysis (like the Huff Model), to analyze spatial data for customer-store relationships? There are a couple ESRI sources (including Business Analyst extension), but I have not seen any for the open-source world. It seems like a place where PostGIS could really be leveraged for its database qualities.   * http://stackoverflow.com/questions/2837870/huff-model-in-gis   * http://arcscripts.esri.com/details.asp?dbid=15999 Reference docs (outdated, but relevant articles explaining the concept):   * Retail Trade Area Analysis Using the Huff Model   * Arc10 Help: Sales Potential Modeling   * Calibrating Huff Model White Paper in ArcGIS Business Analyst   * ICSC Article


OpenLayers: Can I drag a feature between two maps?

Is it possible to drag the features between two different maps? Now, I create feature on event mouseenter but I would like to insert the feature and at the same time start to drag this feature.


What should I start with WebGis Mapserver?

I'm not native English Speaker and I'm a graduated student who want to have a master degree in software engineering. I have a thesis relative with "Build a WebGis for air pollution in Vietnam's capital city". But I've never any experiences with GIS. I've searched some Google, this show me that I should use MapServer, Openlayers and PostGis SQL. Now, I think user will query from web browser and based in OpenLayers function Javascript, It'll transfer data to MapServer (I think can use PHP MapScript here to handle query), after that MapServer can get data from PostGis SQL if it needs (After all, MapServer will return a image that fit all user's query). Please, correct me if I'm wrong or teach me some knowledge. Thanks you for that.


Unable to connect ArcGIS Online through ArcMap/ ArcCatalog ver.10.2

I have ArcGIS Desktop 10.2.I am trying to connect to ArcGIS Online from Arc- catalog (My hosted Services) but throws me an error saying to check Network connection. > Error : " Error Has Occurred . Check your Network connection" But I am able to connect to Arcgis online through web browser. I have ArcGIS Global account & ArcGIS online account as well.


Perform OpenLayers methods when outside images are clicked

Hi (I'm i bit new to OpenLayers). I'm trying to set up my OpenLayers map controls (e.g ZoomIn, ZoomOut) when images elsewhere on the page are clicked. Is this an issue of formatting a control panel to display the buttons as my images (if so how should I set up the CSS to use the images), or would I be better to set up a listener ogn the image, that then runs the method ZoomIn on the when clicked (and If so what sort of code do I need)?


Can we insert arbitrary HTML layers the ESRI ArcGIS JavaScript API?

We would like to implement a completely custom visualization to be included in a map, whose other layers we'd like the JavaScript API to control. This custom visualization would be updated by hand in response to map events, and will be constructed by hand from HTML elements. That is, it is not a layer with simple feature or image behavior as could be created by deriving a custom image, feature, or tile layer. Other than reverse-engineering the DOM constructed by the JavaScript API, is there any support for this cooperation in the API?


Can Representations be used to Spatially Offset (Disperse) XY points for Web Mapping Application?

So I have a bit of an issue of points with the same x and y that I need to display separately from themselves. Here is some history of this issue: I have a database of incidents that happen over a county. These incidents join to a parcel fabric with a one-to-many relationship. So several incidents occur on one parcel. I need the incidents to be shown as a point feature class for a web mapping application. So I added the x and y centroid of the associated parcel and created the point feature class. This resulted in several points being drawn on top of each other as shown in this picture: ![Picture A](http://i.stack.imgur.com/70Acm.png) I converted the symbology to a representation with a 10 meter minimum gap between points which resulted in exactly what I was looking for as show in this picture: ![Picture B](http://i.stack.imgur.com/sPEeZ.png) Now this works great in ArcMap, but when uploaded to my web mapping app the points can only be identified at there original x and y. So when you identify points that have been spaced you get no result, but when you identify the center of the parcel you get several results. What I would love to happen is to somehow return the xy of these representations and change xy of each point to that. I've tried a few programming solutions, but I haven't been able to solve it yet.


How can I convert a tif or xyz file to HGT?

Due to system incompatibilities between projects, I have been asked to convert my DEM which is in geotif format to HGT. I have no experience with HGT and cannot find any export options to this format. Would anyone now if/how I can do this? Yours.


Create point to a center of polyline

I'm trying to create a points in the middle of polylines. The data is now in the form of shapefile. Is there an easy way to do this? Cheers, Sanna


Geoserver WMS-T backend problems

I've been trying to set up a few timed WMS layers in GeoServer. They're simple enough, of the form               ID(PRIMARY KEY) REGION DATE VALUE      so for every region and date you have some value, e.g. the precipitation in that day. When I set up the layer without time dimensions, I get a working layer where I can see all my regions (although each of them is present multiple times, once for every corresponding date). Then, I enable the time dimension, with `attribute = DATE` and `presentation = LIST`. When I call `GetCapabilities`, it really contains something like               <Dimension name="time" default="current" units="ISO8601">       2003-12-31T00:00:00.000Z,2004-12-31T00:00:00.000Z,2005-12-31T00:00:00.000Z     </Dimension>      However, when I request `GetMap`, results vary.   * with MS SQLServer backend, I get blank image if the type of `DATE` column is `date`, but I get the correct map image if it is `datetime`   * with PostGis backend, I always get blank image, whether I use `date` or `timestamp` ( one day granularity is enough for my list, so to represent `2003-12-31` I'm ok with using any timestamp within that day ) Note that GeoServer considers all of these datatypes compatible with the time dimension and allows the user to set them as the time attribute. Has anyone encountered such problems? Am I misunderstanding something about the WMS-T? **EDIT:** I've recently found out that `timestamptz` is the type that works with PostGis. Still, why...?


extract data from several images to different shapefile columns using GRASS

I am now working in grass and I want to extract raster values from several images to a shapefile. I have already created the columns in the .shp where the raster values will be stored but I am facing difficulties on how will I make the loop... What I want is to extract the values of image_1 to column_a, values of image_2 to column_b etc etc... The problem that I have is that I can't make the loop for two variables (raster image and shapefile column) together... It must be easy but I am new in grass and bash in general as you must have already understood. The command that I used is "v.what.rast" Thank you!


Is there easy way to get layers names from WMS server?

I've been looking for information on how to get layers names from certain WMS servers, but I didn't find any. E.g. I have this server: http://sdi.geoportal.gov.pl/wms_prg/wmservice.aspx and I want to know what layers can I get from it. Is there any chance to know their names? Thanks in advance!


How to get info from selected object?

I am new to the Quantum Plugin development and wonder if there is more information about the following. I have added a shape file and am (off course) able to select a point from this shape file. In the shape file I have stored the location (x,y) and an id. Now I would like to be able to select a point in this layer and then my plugin should be able to recognize the id of the point, look up a database and display a graphical representation of the data in the database. So what I am looking for is this,   * how do I get the information of a selected point to my plugin    * is it possible that my plugin overwrites the default information dialog (so the plugin pops up instead of the normal dialog)   * is there perhaps a plugin that already shows such behaviour and I can learn from (haven't found one so far) Thanks (very much) in advance! Rob


How can I rotate a marker in OpenLayers

I'm creating markers using this method :               var markers = new OpenLayers.Layer.Markers( "Markers" );     map.addLayer(markers);     var size = new OpenLayers.Size(21,25);     var offset = new OpenLayers.Pixel(-(size.w/2), -size.h);     var icon = new OpenLayers.Icon('http://www.openlayers.org/dev/img/marker.png',size,offset);     `enter code here`markers.addMarker(new OpenLayers.Marker(new OpenLayers.LonLat(0,0),icon));      Now , I want to rotate the marker 90 degrees to the left (or right). How can I do it? I was able to find example to rotate a feature , but I'm not using a feature.. I'm using a marker. Thx.


Split polygons and extract points

I have a polygon file with 90 adjacent polygons. I also have a lat/long point file that overlaps the entire surface of the polygon file (170,000 points). My problem is that working with all of the data at once is far too demanding and slows the project considerably. If I could have the individual polygons separated and have only the points that are intersecting with those polygons on those separated layers, I could work smoother as I wouldn't have to deal with the entire data set at once. My first idea (which is still in progress) is to do a simple join attributes by location. I say it's still in progress because with 90 polygons and 170,000 points I have been looking at the rainbow loading wheel for a while... Just wondering if this is the best option or if there's a better idea out there. I'd like to be able to work on one polygon at a time and also be able to interact with the points which are associated with that polygon. QGIS on a Mac. Thanks =)


Cut polyline in Qgis 2.4

I want to shorten a feature (a polyline representing a road) in QGIS 2.4 In QGIS 2.0 there was "Split Features" tool in the "Advanced Digitizing" toolbar. Here the icon: ![enter image description here](http://i.stack.imgur.com/5eeHm.png) I'm not able to do this again. Thanks.


How to convert to Australian Height Datum from Google Earth elevation?

I am trying to figure out how to convert from Google Earth elevation to Australian Height Datum (AHD). Google Earth's elevation / altitude is based on The vertical component (altitude) is measured from the vertical datum, which is the WGS84 EGM96 Geoid. **So I assume that WGS84 is Ellipsoidal value.** http://productforums.google.com/forum/#!topic/earth/fBar9afvRV0 The absolute difference between GDA94 and ITRF is now approximately one metre. Since the WGS84 reference frame is now aligned to the ITRF at the centimetre level, the absolute difference between WGS84 and GDA94 is also approximately one metre. **So I ignore the 1 metre difference.** http://www.dse.vic.gov.au/property-titles-and-maps/geodesy/geocentric-datum- of-australia-gda And I use AUSGeoid09 http://www.ga.gov.au/ausgeoid/nvalcomp.jsp to compute. I enter the latitude and longitude from Google Earth and into GDA94 Latitude and GDA94 Longitude text boxes. And I select Ellipsoidal for GDA94 Height (m) and enter the elevation value I get from Google Earth and click on compute. Then the next page will show me the AHD value for this location and assuming that the Google Earth elevation value I entered (WGS84) can have 1 metre difference (I don't know if this is + or - but I can try both +1 and -1). I don't know if I am doing make any sense at all and would appreciate some helps. And what I am trying to do is to compare the Q100 flood level with the AHD level on any given Australian point. Say the council give me a Q100 flood level in AHD, say 10m AHD, and I am trying to find out if the given point has a higher AHD value of 10 or not.


Determine when ArcGIS feature was created

In ArcCatalog I'm looking at a feature's table fields. The DATECREATED column is empty for all features. How can one determine when a specific feature was created?


OpenLayers ArcGIS93Rest symbol size

I'm using OpenLayers 2 to display ESRI WMS data (ArcGIS93Rest layers). The data I'm displaying contains symbols (and sometimes labels) and I'd like to increase the display size of these symbols (and corresponding labels). An example of the data being displayed can be found here. And the web service for that data can be found here. Is it possible to adjust the symbol/label size on my end?   Or am I stuck with the symbol size provided by ArcServer?


Example of a "bleeding" raster in GIS?

I was reading an ArcGIS Help page recently on Polygon to Raster (Conversion) GP tool. There is piece of information there that I became interested in: > If **"bleeding"** or stripes occur in the output raster then use the Check > Geometry and Repair Geometry tools to correct the input feature data. Can anyone describe what bleeding is in terms of a GIS raster dataset / satellite imagery data and if possible supply an image for illustrating this phenomenon.


Adding multiple layers in CartoDB using createLayer() not working

Using CartoDB (cartodb.js 3.5.02), it seems like you should be able to add multiple, independent tile layers to an instantiated Google Map. I've tried using createLayer() a number of ways, using both viz.json and dynamic SQL and no matter what I do, only the last createLayer's tiles are displayed. (e.g. If I use viz.json, both legends are shown but only one set of tiles.) Example loading 2nd layer on 1st layer's `done()`:               cartodb.createLayer(map, url1)         .addTo(map) // ultimately not displayed         .done(function (layer) {             console.log('added url1 ',url1);             cartodb.createLayer(map, url2)             .addTo(map) // displays OK             .done(function (layer) {                 console.log('added url2 ',url2);             })             .error(function (){                 console.log('problem adding 2nd layer');             });         })         .error(function () {             console.log('There is something wrong with requested data!');         });      Example using dynamic SQL:               cartodb.createLayer(map, {         user_name: 'validusername',         type: 'cartodb',         sublayers: [         {             sql: 'SELECT * FROM '+tbl1,             cartocss: '#'+tbl1+'{polygon-fill: #FF6600; line-color: #FFFFFF; line-width: 1; polygon-opacity: 0.7; line-opacity: 1;}'         }]     })     .addTo(map)     .done(function(layer) {         console.log('added ',tbl1);         console.log(map.overlayMapTypes.length); // ==1     }).error(function(layer) {         console.log('problem loading cartodb layer');     });          cartodb.createLayer(map, {         user_name: 'validusername',         type: 'cartodb',         sublayers: [         {             sql: 'SELECT * FROM '+tbl2,             cartocss: '#'+tbl2+'{polygon-fill: #FF6600; line-color: #FFFFFF; line-width: 1; polygon-opacity: 0.7; line-opacity: 1;}'         }]     })     .addTo(map)     .done(function(layer) {         console.log('added ',tbl2);         console.log(map.overlayMapTypes.length); // still ==1     }).error(function(layer) {         console.log('problem loading cartodb layer');     });      I'm guessing that createLayer() resets gmap's map.overlayMapTypes on each call, as its length == 1 even after the second call. Is there a better way to do this, or is this a bug?


Choosing a database for cartesian coordinates

I'm trying to figure out, which database would be the best choice to store cartesian coordinates (x,y,z). I want to query for   * the distance between 2 positions,   * which positions are in a sphere arround a given position,   * which connections between 2 positions intersect with a sphere around a given position. The database should also be able to handle transactions. I have no exerience in any other database then mysql, which doesn't seem to be an option, so I'm open to any suggestion. It'll be something new to me anyway. Which database driver would fit best? Plain JDBC, hibernate, hibernate-spatial (which had the last update in 2011?), or something I haven't had in my mind yet. Thank you in advance for reading and sharing your views.


How to create a Personal Geodatabase

How can I create an Access (.mdb) file containing a personal geodatabase?


Where to download free elevation data for Europe?

Where can I find free elevation data for Europe? Please mention the available resolutions and terms of use when posting a source.


How to filter Legend to show only visible features?

Is it possible to get the legend in a pagelayout to only show patches/swatches for features fall within the visible extent of the Map? The solution needs to work on FeatureLayers and ArcGIS Server layer. It's possible to set a property on the AutoVisibility to filter the Legend to only show the layers that are visible, but if the layer is visible and only a few of multiple symbols in the renderers is visible the legend gets too many items to be useful. Update: This seems to be a question that has been asked several times before on the ESRI-forum, found one solution that seems to works on a FeatureLayer if it has a IUniqueValueRenderer Compressing a legend to show displayed features only but we are using both FeatureLayer and ArcGIS Server layers, so that only solves part of our problem.   * We are trying to find a way to hide and show the IElement from ILegendItem.Graphics , but it feel like a deadend.   * On the server ILegendItem.Layer it might be possible to cast to a MapServerIdentifySublayer and use   Identify to somehow find the visible objects. If that's possible its only a matter of connecting the two.


Does anyone know how to get a feature class from a Map?

I have an axMapControl.Map, I am trying to get a featureClass. I want to use this feature class to call create a GeoProcessor IGeoProcessorResult result = GP.Execute(someFeatureClass, null) as IGeoProcessorResult;


Map service appears in the web REST view but not in ArcMap?

I have an ArcSDE server serving some poly layers through a map service running on ArcGIS Server 10.0. The service appears to be working--I can navigate to it just fine in the REST view and I can see the data when I do the _View In ArcGIS JavaScript_ option. However when I load up ArcMap and attempt to add the service to a layer it appears to succeed but does not show up; the screen remains white no matter what extent I'm viewing. The layer is set to be viewable at all extents and appears to be the correct spatial reference so I'm a bit confused why the javascript viewer can see it but not ArcMap. _edit_ I should add that I have a Silverlight app pointing at the service as well and that also does not show the data.


How to use the transformer KMLRegionSetter ? (Python/FME)

I use Python and FME. I would like to use a transformer "KMLRegionSetter_2" for KML file. I use a fmi file for the transformation.               reader=FMEReader("OGCKML",{'USER_PIPELINE':"C:\\arcfactory.fmi"})                         reader.open("repertoryofkml","") ***Is it correct ?***                         log.log("Reader opened")                              writer=FMEWriter("OGCKML")                         writer.open(repertoryofkml+"_region.kml")                         schemaFeature=FMEFeature()                         log.log("Copying schema features")                         while reader.readSchema(schemaFeature):                             log.logFeature(schemaFeature)                             writer.addSchema(schemaFeature)                         feature=FMEFeature()                         while reader.read(feature):                             log.logFeature(feature)                             writer.write(feature)                         reader.close()                         writer.close()                         log.log("Translation completed.")      The arcfactory is                   DEFAULT_MACRO WB_CURRENT_CONTEXT     # -------------------------------------------------------------------------     # The region extent is set to be       # calculated based on the extent        #  of incoming features.     Tcl2 proc KMLRegionSetter_2_bounding_box_setter { minx maxx miny maxy} { \         if { [string compare {Yes} {Yes}]==0 } {                           \           global FME_CoordSys;                                             \           if { [string length $FME_CoordSys]>0 } {                         \              FME_Execute Bounds kml_latlonaltbox_west kml_latlonaltbox_east kml_latlonaltbox_south kml_latlonaltbox_north; \               FME_Execute Reproject \"$FME_CoordSys\" LL84 kml_latlonaltbox_west kml_latlonaltbox_south; \               FME_Execute Reproject \"$FME_CoordSys\" LL84 kml_latlonaltbox_east kml_latlonaltbox_north; \            } else {                                                        \               FME_LogMessage fme_warn \"KMLRegionSetter: A valid coordinate system is required for calculating the region\'s bounding box\"; \            }                                                               \         } else {                                                           \            FME_SetAttribute kml_latlonaltbox_west \"$minx\";               \            FME_SetAttribute kml_latlonaltbox_east \"$maxx\";               \            FME_SetAttribute kml_latlonaltbox_south \"$miny\";              \            FME_SetAttribute kml_latlonaltbox_north \"$maxy\";              \         }                                                                  \     }          FACTORY_DEF * TeeFactory                                               \        FACTORY_NAME KMLRegionSetter_2                                      \        INPUT  FEATURE_TYPE BoundingBoxAccumulator_BOUNDING_BOX             \        OUTPUT FEATURE_TYPE KMLRegionSetter_2_OUTPUT                        \                kml_lod_min_lod_pixels "1500"                               \                 kml_lod_max_lod_pixels "-1"                                \                 kml_lod_min_fade_extent  "0"                               \                 kml_lod_max_fade_extent "0"                                \                 @Log("Before")                                             \             @Tcl2("KMLRegionSetter_2_bounding_box_setter {<Unused>} {<Unused>} {<Unused>} {<Unused>} ")             @Log("After")                                              \      Is there a way I can find out if the product is correct?


Adding table to the MapServer so the layers and tables can be associated

I'd like to add tables to my MapServer. I want it to include both feature layers and tables which enables me to associate the layers with the relevant tables and retrieving the necessary fields of the tables. The resulting structure will be like the one in the following link; http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Petroleum/KSPetro/MapServer After clicking on the "tops" table, the relationship between the layers and the table "tops" can be seen. Though all the necessary tables and layers can be seen through ArcCatalog, it cannot be seen in the MapServer. After updating the ArcCatalog, The MapServer is reseted. Can anyone help me? Thanks a lot.


pgRouting: Is it possible to do multiple (concurrent) Dijkstra/A*/A_shooting_star queries at a time?

_Disclaimer: the author of the question is a novice in PostgreSQL and pgRouting._ As I understand doing a shortest path query in pgRouting is a complicated SELECT underneath. And as I know unlike any UPDATE queries, SELECT queries in PostgreSQL can be done simultaneously, because they don't interfere with the the database integrity anyhow. If the above is correct, the question is: **Can I query pgRouting for shortest paths, for example, each 1 millisecond and get the same timing results as in case with truly sequential shortest path queries? Is case 2 possible?** Usual case (1):   * [Time elapsed: 0 seconds]   * Query for shortest path A   * Get result for the shortest path A   * [Time elapsed: 1.5 seconds]   * Query for shortest path B   * Get result for the shortest path B   * [Time elapsed: 3 seconds] A case with simultaneous queries (2):   * [Time elapsed: 0 seconds]   * Query for shortest path A   * [Time elapsed: 0.001 seconds]   * Query for shortest path B   * Get result for the shortest path A   * [Time elapsed: 1.5 seconds]   * Get result for the shortest path B   * [Time elapsed: 1.5001 seconds]


How can I determine what fonts are used by an mxd?

A client has sent me an mxd and a file gdb. When I look at the symbols, they don't look good. I think they need to send me some fonts. Is there some way I can use arcmap to determine the name of the font file I need so that I can request it from them?


Does GPS signal quality depend on the chip manufacturer? Does it depend on weather?

_(Sorry if GIS is not the right place to post this question to)._ Recently me and my school friends had a GPS software application project to pursue at the university. A device very similar to this one was used by the application. One day it refused to show us our current location - it was continuously showing a point in the Atlantic Ocean instead of land [we were outside of any buildings]. I did a double check by opening a default map application on an HTC Desire with Android 2.1 - it showed no current location as well. Questions:   1. Does GPS signal quality depend on the chip manufacturer?   2. Does GPS signal quality depend on weather?   3. Is it possible to have a commercial hardware-software system which never loses the GPS signal and always shows the correct current position of a user?


How can you auto-populate field using spatial location of another feature and its attributes?

I want to auto-populate a field based on the spatial location of another feature's attribute. Add a point on top of a building. The point automatically adds the name of the building. This seems like a standard work flow. Does anyone know how to do this? Is it an event trigger? The goal is to assist field workers using what seems like simple GIS logic. Thank you


Composite Symbol in FlexViewer 2.2

I have two questions regarding picture marker symbol in flex viewer:   1. How can I make a composite symbol so that users can re-size and drag it. Any example code could help a lot.   2. I have three symbols (2 text and a picture marker symbol) in a composite symbol. A picture marker symbol is drawn where the user exactly clicks on the map. One text Symbol on the right and the problem is with the left text symbol. I am not able to place it on the left side. By setting its x offset property to 0, it centers it self in the picture marker symbol. By setting x offset to negative the result is same as setting it to 0. Any ideas? Thanks in advance


Creating shapefile from selection - remove from map

I am iterating over a shapefile and creating a new shape from each row. I will be creating several thousand individual shapes and do not want to inundate my TOC with that many layers (I bet ArcMap would crash if I did). Using the code below, each shape is added after being created. How could I remove the shape from the TOC after being created? I tried deleting the tempPoly variable but that did not do the trick.               polys = arcpy.SearchCursor(shapefile) #recall the cursor     for poly in polys:          print('starting at '+str(poly.FID))         whereClause = '"FID" = ' + str(poly.FID     ) # Create a clause to select only the current record         tempPoly=arcpy.FeatureClassToFeatureClass_conversion(shapefile,tempFilesPath,"tempPoly"+str(poly.FID),whereClause)                      I am not working in a dataframe and am in the data view not the layout view.


Create and download pdf file in nodejs express application?

I creating web application using nodejs express. I am using jquery and bootstrap for responsive web design. In .ejs file I have one Date,Preview and Download button, send the request to server(fetch data from database) and create a PDF dynamically and then show that PDF response in print preview if user click print preview button or download that PDF response if user click download button. I seen one example to dynamically create PDF as file and stored local disk. (http://www.codeproject.com/Tips/755694/Generating-Server-Side-PDFs-using- PDFKit-and-Node) Is there any option to download the PDF without writing as file?


Georeferencing Vector Layer (shp) from Mollweide Projection to Custom CRS in QGis

the title might be a little complex. Its part of a massive project: I'm working on a fantasy world; a map, to be more specific. I basicly just started to paint a world map in Photoshop, but over time it became very big an unfortunatly photoshop is not realy good with detailed world maps. so i went out to look for another software to manage coastlines, rivers, citys, town, borders, streets and much much more. I decided to use Qgis, imported my .psd as .tif and started to vectorize it manualy (yes, it took me quite long and i haven't finished yet). The worldmap is a projection of a real planet. I never set up any CRS. The problem is, i never thought of any projection-issues before. Later i decided, that the painted map is a "mollweide" projection of my planet. (i know this will cause some disortion, but thats okay) To make it easier, i decided the planet to be a perfect sphere with r=10567km. Since i am a newbie on qgis, i have three issues now: 1) I have no good idea, how to define a custom CRS and there is no tutorial for doing that. 2) I have no idea how to georeference my vectorlayer. I worked on a mathamtical way to transform the mollweide-x,y-coordinates in Qgis to real latitude-longitude- coordinates. But i dont know how to perform the algorythm on my shapefile (i thought of exporting it to GeoJSON) and get QGis that to display the geocoordinates using my custom CRS after transforming. 3) Is there a way to keep my background raster layer after transforming the vectrolayer so i can go on vectorizing? Many thanks in advance and sorry for bad grammar, im german. MX117


What is a simple python code to practice with in arcgis?

I am trying to familiarize myself with python code. Could someone give me a simple code with an explanation of what it does so I can practice? Or a few codes with explanations if you have the time


Random-Forest Classification of 10cm Imagery for species-distribution in R (no point-shapes)

I'm actually trying to classify 10cm-resolution images with the RF-package. I do this to separate some species in the forest, seen on my images. While I was searching for an answer, I found the following code, bit I don't understand why the images have to be transformed into point-shapes, so I'm looking for a way to perform a RF-classification just with Raster (*tif, *png). The Code I found (made by Mr. Evans): * * *                   require(sp)         require(rgdal)         require(raster)         require(randomForest)          # CREATE LIST OF RASTERS         rlist=list.files(getwd(), pattern="img$", full.names=TRUE)           # CREATE RASTER STACK         xvars <- stack(rlist)                # READ POINT SHAPEFILE TRAINING DATA         sdata <- shapefile("inshape.shp")          # ASSIGN RASTER VALUES TO TRAINING DATA         v <- data.frame(extract(xvars, sdata))          # RUN RF MODEL     ## assumeing that sdata has a variable called 'train' with e.g. 0 and 1 values          rf.mdl <- randomForest(x=v, y=as.factor(sdata$train))     ## or for regression:         rf2 <- randomForest(x=v, y=sdata$train)                  # CHECK ERROR CONVERGENCE         plot(rf.mdl)          # PLOT mean decrease in accuracy VARIABLE IMPORTANCE         varImpPlot(rf.mdl, type=1)          # PREDICT MODEL         predict(xvars, rf.mdl, filename="RfClassPred.img", type="response",              index=1, na.rm=TRUE, progress="window", overwrite=TRUE)      * * * My Questions:   1. At "Read Point Shapefile Training Data", why cant I use just raster? I don't get the "jump" to point-shape   2. In my understanding, I need to create a raster-stack and some training-areas, which are imported as raster's as well. Then I perform rf-classification and plot the results. Am I right?


UTFGrid and custom tiles in OpenLayers

This is my first post here so I apologize in advance if a convention is escaping me in the question format. I am trying to display information from utfgrid in OpenLayers. I am using custom tiles in a XYZ format which I have setup as a baselayer. I have added a utfgrid layer using the openlayers demo but I cannot get it to work. The goal is to have information show up on mouse over events. The information from UTFGrid is passed to a div on the main html page. Main html page: `               <style>         #attrs {             height: 1.5em;         }     </style>               <div style="width:100%; height:100%" id="map"></div>     <div id="attrs"></div>      ` main.js               var map;          function init() { map = new OpenLayers.Map ("map", {                      restrictedExtent: new OpenLayers.Bounds(-157.3251,28.3044,-39.9032,76.5986).transform("EPSG:4326", "EPSG:900913"),                 units: 'm',                 numZoomLevels: 8,                 projection: new OpenLayers.Projection("EPSG:900913"),                 displayProjection: new OpenLayers.Projection("EPSG:4326")             } );                  // This is the layer that uses the locally stored tiles             var OLMCLayer = new OpenLayers.Layer.XYZ(             "Local Tiles",              "tiles/${z}/${x}/${y}.png",              {             type: 'png',             isBaseLayer: true});             map.addLayer(OLMCLayer);             // This is the end of the layer                  //layer for interactive grid             var utfgrid = new OpenLayers.Layer.UTFGrid({             url: "tiles/${z}/${x}/${y}.json",             utfgridResolution: 4, // default is 2             displayInLayerSwitcher: false             });             map.addLayer(utfgrid);                       //callback             var callback = function(infoLookup) {                 var msg = "";                 if (infoLookup) {                     var info;                     for (var idx in infoLookup) {                     // idx can be used to retrieve layer from map.layers[idx]                         info = infoLookup[idx];                         if (info && info.data) {                                  msg += " + info.data.csdname + ";                                 }                     }                            }                 document.getElementById("attrs").innerHTML = msg;             };                  var utfControl = new OpenLayers.Control.UTFGrid({             callback: callback,             handlerMode: "move"             });             map.addControl(utfControl);                  map.addControl(new OpenLayers.Control.ScaleLine({'geodesic': true}));                  if( ! map.getCenter() ){                 var lonLat = new OpenLayers.LonLat(lon, lat).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());                 map.setCenter (lonLat, zoom);                  }              }


Problem measuring area with gps coordinates

I am trying to measure area from gps coordinates but fail to get the correct result (7200 square meters). I used the formula from this post but I get way too high number as result (should be in square meters). Here is my current work in jsfiddle. Any idea what is wrong?               Math.radians = function(degrees) {       return degrees * Math.PI / 180;     };          area = Math.radians(x2 - x1) * (2 + Math.sin(Math.radians(y1)) + Math.sin(Math.radians(y2))) + Math.radians(x3 - x2) * (2 + Math.sin(Math.radians(y2)) + Math.sin(Math.radians(y3))) + Math.radians(x4 - x3) * (2 + Math.sin(Math.radians(y3)) + Math.sin(Math.radians(y4))) + Math.radians(x5 - x4) * (2 + Math.sin(Math.radians(y4)) + Math.sin(Math.radians(y5)));          area = Math.abs(area * 6378137.0 * 6378137.0 / 2.0)     alert(area);


Using Mosaicking Images in Erdas software

Do you know any dissertation which has written about Mosaic briefly?   I did the Mosaic for my Landsat images but i want to explain and write about but i do not know how and what shall i write about it ? is here any dissertation has written the mosaic briefly? Sorry for my bad English so that is why i do not know how to write so i really needs 100 word for this process ...if someone helps me ...i will appreciate your help.


QGIS Gazetteer Plugin connection to internal database

A few posts on here mention that the Astun QGIS-Gazetteer-Plugin could be adapted to reference a PostGIS database. Has anyone done this adaptation and could share it? I want to use a gazetteer stored in a PostGIS database, but don't want to have to create a webserver.


How do I get the centroid of line with OGR

Can somebody explain how to get the centroid of a feature with ogr? I have no idea what the `centroid()` function itself does.               >>> linelyr = lineshp.GetLayer()      >>> f = linelyr.GetFeature(0)      >>> g = f.geometry()     >>> g.GetPoint()     (5.85136, 49.974, 0.0) # starting point of the line          c =g.Centroid()     >>> c.GetX()     0.0


Export attribute table (feature class) to text file in batch?

What would be the most efficient way to export attribute tables from multiple feature class files stored in a file geodatabase? Export to .txt or .csv. Is there any sort of batch process? Or python script? I have hundreds of files within this geodatabase and really need to automate this process.


List the projection & datum of all the files in a folder

In QGIS/GRASS, is it possible to list the projection details of all the shp,tab,dxf files in a folder ? We are having 100 - 150 files in too many folders. We would like to create a table of Proj details of all the files in those folders. Any idea ?


Visualize bounding box to square like polygon

I want to add script in my plugin to visualize bounding box into a polygon shape, bounding box i try to visualize have format like this:               (X1,Y1) (X2,Y2) (X1,Y2) (X2,Y1)      Does QGIS/PYTHON have modul/script to do such thing?


MYSQL 5.6 Cluster / chain points by distance to any other point without millions of calculations?

I have a table of approx 10,000 - 20,000 dynamic points across the globe stored as lon/lat points. I want to cluster any point within (roughly) 3km of any other point into one point (and return the averaged center point of each cluster if possible). Unlike some other solutions I have seen, I do not just want points within 3km of the central cluster point, it is fine to have a point within each cluster many kilometres away from the central cluster point as long as there is a chain of points within 3km of each other joining the points together into a single chain/cluster. The only way I can think of doing this is looping over every point, finding any other points within 3km of that point, and then recursively each of those points etc until i find all in that perticular chain/cluster, and then repeat for all the remaining un-clustered points - this would result in millions of calculations. Is there an easier way of doing this? Preferably with MYSQL 5.6 geospatial abilities, but im open to any viable solution.


PostGis geometry name lookup failed for table

I have a table name erpAssets which has column name Region of type polygon. it contains entries of points also like (-79.4609576808001,43.9726680183837)). I have written query which convert these points to geometry which is used by mapnick to generate tiles. ( SELECT replace(concat(concat('POINT',concat(trim(TRAILING ')'FROM concat('(',trim(LEADING '(' FROM region::TEXT)::TEXT) ),')')),''),',',' ') as data from "erpAssets" where parent=326815) as foo   ) as points My osm.xml file is as follows:               <?xml version="1.0" encoding="utf-8"?>     <!DOCTYPE Map [     <!ENTITY % entities SYSTEM "inc/entities.xml.inc">     %entities;     ]>     <Map background-color="#bb0000" srs="&srs900913;" minimum-version="2.0.0">       &fontset-settings;      <Style name="theme_park">          <Rule>           <PointSymbolizer file="&symbols;/alpinehut.p.16.png"                 />              </Rule>          </Style>          &layer-shapefiles;     <Layer name="theme_park" status="on" srs="&osm2pgsql_projection;">         <StyleName>theme_park</StyleName>         <Datasource>           <Parameter name="table">             (SELECT ST_GeomFromText(data)     FROM     (     SELECT replace(concat(concat('POINT',concat(trim(TRAILING ')'FROM  concat('(',trim(LEADING '(' FROM region::TEXT)::TEXT) ),')')),''),',',' ') as data      from "erpAssets" where parent=326815) as foo                    ) as points                </Parameter>           &datasource-settings;         </Datasource>     </Layer>     </Map>      Tiles are not generated and i am getting error on console as follows: Postgis Plugin: geometry name lookup failed for table '"erpassets"'. Please manually provide the 'geometry_field' parameter or add an entry in the geometry_columns for '"erpassets"'. I have converted region column into geometry by aliasing then why i am not getting points on map?


Using OGR Intersection Method Python

I'm currently working to find the intersections between linears in a shapefile. I'm a newbie to the GDAL/OGR library. I've done some googling and came up with what seems to be a useful example(see below). There is a problem though. I don't see the method ExportToWkt(). My intellisense(or whatever it's called in IDLE) for the variable "intersection"doesn't have that option. Can anybody tell me what I'm doing wrong. Or just give me some general guidance to comparing two features in a shapefile and finding the intersection(if they intersect at all). Thanks. ![enter image description here](http://i.stack.imgur.com/xcFyf.png)               from osgeo import ogr          wkt1 = "POLYGON ((1208064.271243039 624154.6783778917, 1208064.271243039 601260.9785661874, 1231345.9998651114 601260.9785661874, 1231345.9998651114 624154.6783778917, 1208064.271243039 624154.6783778917))"     wkt2 = "POLYGON ((1199915.6662253144 633079.3410163528, 1199915.6662253144 614453.958118695, 1219317.1067437078 614453.958118695, 1219317.1067437078 633079.3410163528, 1199915.6662253144 633079.3410163528)))"          poly1 = ogr.CreateGeometryFromWkt(wkt1)     poly2 = ogr.CreateGeometryFromWkt(wkt2)          intersection = poly1.Intersection(poly2)          print intersection.ExportToWkt()


Transforming between epsg:3857 and Google Maps Tile coordinates

Hio, I used to use a simple python project (https://github.com/hrldcpr/mercator.py) to convert between wgs84 and google maps tile coordinates. This project doesn't have a license, and looks like it may be inaccurate (assuming a spherical earth?), so I decided to use pyproj. I understand that google maps uses a projection called epsg:3857 to draw their tiles. When I convert from wgs84 to epsg:3857, I get numbers that I just don't understand:               >> import pyproj     >> epsg3857 = pyproj.Proj(init='epsg:3857')     >> wgs84 = pyproj.Proj(init='EPSG:4326')     >> latlng = (45.618, -73.604)     >> pyproj.transform(wgs84,epsg3857,latlng[0],latlng[1])     (5078172.5310075525, -12357511.560866801)      I know that the lat,lng coordinate I took is in the tile `http://b.tile.openstreetmap.org/11/605/731.png`, But I just can't figure out how to go from the returned numbers to the tile coordinates. Firstly, the numbers shouldn't be negative (tile coordinates are positive). Trying different scales based on the 11 zoom levels, I just can't figure this out. Searching the internet, I can't figure out what the epsg:3857 coordinates actually denote.


How to rasterize SpatialPolygons in R?

I'm trying to extract the bathymetry values of my area of interest from a world bathymetry raster layer using the 'rasterize' function in the {sp} package. *Edits: I found the 'extract' function which seems to be more what I'm looking for. This is what I've done so far:               > class(subarea0) #This is my area of interest (Eastern Canadian Arctic Sea)     [1] "SpatialPolygons"     attr(,"package")     [1] "sp"          > extent(subarea0)     class       : Extent      xmin        : -82.21997      xmax        : -57.21667      ymin        : 60.2      ymax        : 78.16666          library(marelac)     data("Bathymetry")#World bathymetric data in library (marelac)     names(Bathymetry);class(Bathymetry);str(Bathymetry)     [1] "x" "y" "z"     [1] "list"     List of 3      $ x: num [1:359] -180 -179 -178 -177 -176 ...      $ y: num [1:180] -89.5 -88.5 -87.5 -86.5 -85.5 ...      $ z: num [1:359, 1:180] 2853 2873 2873 2873 2873 ...            raster_bath<-raster(Bathymetry)#Transformed into a raster layer         extent(raster_bath) <- extent(subarea0)#Transform the extend of my raster to the extend of my SpatialPolygons          >ras_sub0<-rasterize(subarea0,raster_bath)#rasterize my SpatialPolygons (*Edits: not the function that I need here, but I am still interested to learn what results mean)     Found 2 region(s) and 10 polygon(s)     > plot(ras_sub0)     > plot(subarea0, add=TRUE)      ![enter image description here](http://i.stack.imgur.com/nJMrB.jpg)               > ras_sub0     class       : RasterLayer      dimensions  : 180, 359, 64620  (nrow, ncol, ncell)     resolution  : 0.06964709, 0.0998148  (x, y)     extent      : -82.21997, -57.21667, 60.2, 78.16666  (xmin, xmax, ymin, ymax)     coord. ref. : +proj=longlat +ellps=WGS84      values      : in memory     min value   : 1      max value   : 2      layer name  : layer       I don't understand the result. Why am I getting 2 colors for each of my polygons? What do they mean? How can I ultimately get bathymetry depth contour? Is this something to do with my resolution or changing the dimensions? *Edits: ok, I've now done the following:               v <- extract(raster_bath, subarea0)#Extract data from my Raster Layer for the locations of my SpatialPolygons      v is a list and I am not quiet sure how/under what form to rebind this info with my spatial polygon... Thank you!


IFeatureLayer.Seach() throws exception HRESULT:0x80041538

My code as bellow give error HRESULT:0x80041538 whenever I use GROUP BY or ORDER BY postfix. Trying in Personal(.mdb) and MSSQL database datas - same result. What can be the reason. Asked similar question before, but according to what I found that time, in MSSQL it should be working.               IQueryFilter qf = new QueryFilter();     ((IQueryFilterDefinition2)qf).PostfixClause = "GROUP BY " + groupbyfields;     ILayer layer = Utils.getLayer(map, layer_name);     ICursor ccursor = null;      cursor = ((IFeatureLayer)layer).Search(qf, false);


Looking For Free Global Bedrock Geology Data

I've searched around for a freely available global bedrock geology data set, but I have yet to find one. Anyone come across such dataset?


Can QGIS Read Spatialite Views?

I have a spatialite database I created that spans several years of crime data. To facilitate a real-world scenario where I may simplify the interaction for a user by introducing a View that simply limits the time span or what types of crimes are returned, I want to know if it is possible for QGIS to read this View like it would any other spatial table in my database. The point here is that I obviously do not want to create a separate table for every possible View I may use, and I am trying to make it simple by not requiring the user to know the database and the appropriate SQL to subset the data themselves. A similar workflow in the ArcGIS world might be creating separate layer files that the user could open in ArcMap that access the database (say, SQL Server) and present only the limited data set. I created a View in my database, but it does not show up in the list of feature classes I can import when I connect to the spatialite db in QGIS. Maybe Views aren't considered spatial? (This is something I'm going to look into later, but I thought I already did; I just don't recall the conclusion.) In any case, how might one replicate the sort of work flow I want or the similar ArcGIS alternative?


Node.js transformation from NAD83 to WGS84

I've used the excellent npm shapefile library to import Canadian electoral districts into MongoDB. Here's a sample file: http://ftp2.cits.rncan.gc.ca/pub/geott/electoral/2011/fed308.2011.zip Is anyone familiar with a node.js tool that would allow me to do this? I'm familiar with Django and the GIS tools provided by Geodjango, but am new to GIS development in the Node.js ecosystem. Thanks in advance!


Attribute inspector not editable - FLEX or Javascript

I am using ArcGIS 10.2. I have an application that is using the editor and the attribute inspector. I need to add a string showing the current date to a field. Everything works but after creating the feature and selecting it again I can see the string in that field in the attribute inspector but the attribute inspector is not editable anymore for that feature. Is it possible to add a string to a field and still have that feature editable in the attribute inspector? Thanks                   var    currDateTime:String = ""         private function drawEnd(event:DrawEvent):void            {             dateFormatter.formatString = 'YYYY/MM/DD HH:NN:SS';           currDateTime = String(dateFormatter.format(dtCurrent) + '.' + dtCurrent.getMilliseconds());                    FeatureLayerstewardship.addEventListener(FeatureLayerEvent.EDI}TS_STARTING, editsStartingHandler);                    }                 private function editsStartingHandler(event:FeatureLayerEvent):void                     {                         if (event.adds)                         {                                  event.adds[0].attributes['DrawDate']  =  currDateTime;                         }                               }


How to set up ArcGIS Server 10.1 test environment on Mac laptop with VMware?

In my production environment I have ArcGIS Server 10.0 Enterprise, ArcSDE 9.3, and ArcIMS. I want to shut down ArcIMS as soon as possible for obvious reasons, and upgrade ArcSDE 9.3 to 10.1 and ArcGIS for Server 10.0 to 10.1. As I am new to ArcGIS for Server 10.1, I would like to set up a test environment just to get to know the software architecture but will not be able to do this on my network at work. I would therefore like to do this on my laptop with VMware. Could anyone guide me as to how I should do this on my Mac with VMware?


openlayers Arcgis WFS mousehover

i have a problem using ArcGIS wfs layer in openlayers. I would like to add the layer to the map as vector layer and then using a mousehover to highlight the features. However i cannot bring it to work. Code example:               var buildings_wfs = new OpenLayers.Layer.Vector("Buildings_WFS",                        {strategies: [new OpenLayers.Strategy.Fixed()],                         visibility: true,                         protocol: new OpenLayers.Protocol.WFS.v1_1_0({                         srsName: "EPSG:3857",                         version: "1.1.0",                         featureType: "Buildings",                         url: "http://XXX/MapServer/WFSServer",                         featureNS: "http://XXX/MapServer/WFSServer",                         geometryName: "Shape",})});      any help is much apreciated.


How can I move two layers at once in QGIS?

I'm trying to move two digitized layers, one containing points, the other polygons to a different location at the same time. QGIS doens't seem to allow this. Even if I select both layers and features it will only move one (the one I last selected, so which ever feature is shown in editor) I know ArcGIS allows multiple layers to be moved at once, just with the moving tool or with the spatial adjusment. I haven't been able to reproduce this in QGIS. Thanks for any help!


Linking sld to vector layer

I have created a vector layer by reading a geojson file and I have a SLD file created for this layer. I am wondering how do I link the SLD file to the layer. I had a read of this example on Openlayers website: http://openlayers.org/dev/examples/sld.html I am having a bit of trouble understanding the code for this example- which are using radiobuttons to change the style to the selected button. I believe the linking in my situation will be much simple than what is showing in the example- just linking one SLD file to one single vector layer. Any guidance will be greatly appreciated.


Coxcomb chart in qgis

I would like to use special pie chart for my map, where the angle is not important, but area or radius of the arc carries information. I found, that this type of pie chart is calling Coxcomb/polar/rose (in Czech it is known as comparative) chart (see http://blogs.sas.com/content/jmp/files/2012/03/spending1.png or http://visual.ly/learn/coxcomb-chart), basicaly it is bar chart masked in pie :). Do you have any suggestions how to create this chart automaticaly or semiautomaticaly in gis (I prefer QGIS)? Thanks for help, Daniel


Looking for free/paid RSS to GeoRSS converters

I am looking for an RSS to GeoRSS converters . I was able to find only one converter i.e. GeoNames (its crashing some-times) and Meta-carta (looks like closed) So does anyone knows free/paid RSS to GeoRSS converters ? Software's : ArcGIS Suit 10.1 & ArcGIS JSAPI 3.3/3.4 Thanks in advance : )


ArcGIS Geoprocessing Script - Calling External EXE Works in Desktop - Causes GP Service to Quit Abruptly

I have an interesting problem on my hands... I have a generic python script that does a bunch of geoprocessing functions using the standard arcgisscripting module (Yes, I am still at 9.3.1). At one point in this script, I call out to an external exe. This external exe does some heavy duty raster processing using gdal17.dll. After the .exe does its thing, my script continues on doing additional processing using the results from the .exe - still using arcgisscripting functions. The tool runs beautifully in a desktop environment. However, as soon as I publish it as an ArcGIS Server Geoprocessing Service - it exits abruptly in the first calling of arcgisscripting function **AFTER** the gdal-based exe is called. I can't log or trap an error - it just plain 'ol quits. I am very aware that mixing gdal in the arcgis geoprocessing environment is looking for trouble. However, porting the logic from the exe is just not an option at this point - if it is even possible. The fact the script works fine in the desktop environment gives me a glimmer of hope that it may work in a gp service. Any suggestions greatly appreciated.


How do you choose the classifications on choropleth maps?

I find myself more and more struggling over defining break points when displaying choropleth (aka thematic) maps to view by _others_. Does anyone have any suggested references that help guide, both how to choose the type of scale used _and_ the appropriate number of break points? In particular for the number of bins I have only ever seen arguments for a limiting number (e.g. you should not use any more than 5). * * * To be more specific about what I am looking for, most references I have come across about the subject are similar to the document referenced by julien in this post, and I'm just looking for a more in-depth discussion about the topic. A few specific use cases I come across frequently (for examples of my struggles);   * When displaying data that has a large right skew, I'm typically hesitant to display an exponential scale. I fear (for the audiences I am typically displaying maps to) this would cause a greater amount of cognitive burden reading the scale and mapping actual attribute values to the colors. Are my fears incorrect? Also for these types of distributions I find it difficult to justify any particular number of bins.   * When displaying many small multiple maps, how do I choose an appropriate scale that allows one to visualize relationships effectively both within and between the small multiples? My de-facto standard when the attribute scales vary to a great extent is to use quintiles within each seperate distribution. Are quintiles too many classifications and creating too great a cognitive burden to compare between the panels? I assume people understand quantile classifications are equivalent to rankings (and thus when classed that way aids in interpreting between panels), is this assumption correct? I initially wrote a paragraph trying to describe the goals of such maps, but I suspect my goals are pretty typical so it was unneeded. The only thing to clarify again is that these are for viewing by other people (like in reports, publications) and are not really for my own exploratory data analysis (although I would suspect good advice should translate to either). Perhaps a good reference may describe the potential goals of such maps, and trade-offs associated with using different classification schemes. I would be interested in both specific and general references.


Where can I download all 3,141 County US Polygons clipped with high resolution shoreline data?

After having done quite a bit of research I have been unable to find a single shapefile download which includes all of the current 3,141 counties with their associating data clipped with the highest resolution shoreline data available. Does anyone know where I can find this data?


How to delete a table field in ArcGIS?

I am trying to delete a table field: From ArcMap table view, I right click on the field heading and select `Delete field`. Unfortunately, I obtain the following message:               Failed to delete the selected fields.     General function failure [TABLE_NAME]      and the field remains. How should I proceed to delete this damned field?


How to query distict row with the same label from different linestring with multiple segment?

I have a multilinestring street table in postgis with two columns: label and prefix. This table has 2 different roads with the same name and each road contains multiple segments. Roads were splitted on each intersection during authoring in QGIS so that the table has total 14 rows. How to query the two so that i have two unique street rows with prefix and label column in the result?


Splitting raster pixels by a polygon's edge?

I have a a polygon shapefile of different regions, and a raster grid of precip data. I want to take the polygon and add up all the raster precip data in each zone. I could use zonal statistics to do this, however the tool does not split pixels exactly where the polygon edge cuts through the a pixel, it instead takes either the whole pixel value or not at all. I could convert the raster data to polygons, but I was wondering if there was a way to do this without going to polygons.


DEM sources for arctic regions

Are there any 90m DEMs out there for regions north of where the SRTM dataset ends? I looked at ASTER, but it seems to have a lot of unfilled voids, and it's important that the resolution matches the datasets I already have.


JTS difference op followed by an intersection op not returning expected results

I have two overlapping polygons and I want to get the line segment(s) where the edges cross. ![enter image description here](http://i.stack.imgur.com/z6gE3.png) So I begin by performing a Difference operation. That gives me the area where A is "outside" of B. ![enter image description here](http://i.stack.imgur.com/Wtl0k.png) Then I do an Intersection op. I expect that to give me the line segment where the two polygons "touch", but as you can see I get a smaller than expected result that doesn't extend along the entire edge where they touch. You can see in the above shot where the green result is, but here it is isolated from the two polygons. ![enter image description here](http://i.stack.imgur.com/aTNLw.png) What am I doing wrong? Is there a better way to go about this?


Issue selecting feature for IdentifyTask (Javascript API)

I am having an issue selecting features in my web map for an IdentifyTask operation. I have a dynamic map service that contains a few sublayers that I would like to be able to click and have a popup or infowindow display the attribution for the selected feature. Currently onclick of the "map", the IdentifyTask execution fires off. The problem is that the precision of the map click seems to be off. When I click a feature with the cursor, the feature is not selected and the InfoWindow displays 'No Results' way below where I clicked the cursor. The InfoWindow typically is supposed to display where a user clicks the cursor right? I have to click above the intended feature in order to actually select the feature and have the IdentifyTask recognize it. Its weird. I played around with the tolerance values for the IdentifyParameters object but no luck. Has anybody ever had a similar issue? Is there a way to specify the precision for a mapClick event? Any help would be greatly appreciated. Below is the code I'm using to show the results of the IdentifyTask.               //Create IdentifyTask object     userConfig.identifyTask = new esri.tasks.IdentifyTask(currentServiceUrl);          //Create and setup IdentifyParameters     userConfig.identifyParams = new esri.tasks.IdentifyParameters();     userConfig.identifyParams.height = userConfig.map.height;     userConfig.identifyParams.width = userConfig.map.width;     userConfig.identifyParams.mapExtent = userConfig.map.extent;     userConfig.identifyParams.tolerance = 3;     userConfig.identifyParams.returnGeometry = true;          //Define the layers to identify     var layersToId = [];     if (currentUtilId == "barksdale") {         var layers = userConfig.barksdaleService.visibleLayers;         for (var i = 0; i < layers.length; i++) {             if (layers[i] != 27 && layers[i] != 40 && layers[i] != 82) {                 layersToId.push(layers[i]);             }         } //End loop     }     else if (currentUtilId == "malmstrom") {         var layers = userConfig.malmstromService.visibleLayers;         for (var i = 0; i < layers.length; i++) {             if (layers[i] != 27 && layers[i] != 40 && layers[i] != 82) {                 layersToId.push(layers[i]);             }         } //End loop     }     else if (currentUtilId == "minot") {         var layers = userConfig.minotService.visibleLayers;         for (var i = 0; i < layers.length; i++) {             if (layers[i] != 27 && layers[i] != 40 && layers[i] != 82) {                 layersToId.push(layers[i]);             }         } //End loop     }     else if (currentUtilId == "whiteman") {         var layers = userConfig.whitemanService.visibleLayers;         for (var i = 0; i < layers.length; i++) {             if (layers[i] != 27 && layers[i] != 40 && layers[i] != 82) {                 layersToId.push(layers[i]);             }         } //End loop     }     else if (currentUtilId == "warren") {         var layers = userConfig.warrenService.visibleLayers;         for (var i = 0; i < layers.length; i++) {             if (layers[i] != 27 && layers[i] != 40 && layers[i] != 82) {                 layersToId.push(layers[i]);             }         } //End loop     }     userConfig.identifyParams.layerIds = layersToId;     userConfig.identifyParams.geometry = evt.mapPoint;          var deferred = userConfig.identifyTask.execute(userConfig.identifyParams);          deferred.addCallback(function (response) {         // Response is array of identify result objects         // Return an array of features.         return dojo.map(response, function (result) {             var feature = result.feature;             var attribution = feature.attributes;             var infoTemplate = new esri.InfoTemplate();             var templateString = "";             //Parse and print the key-value pairs in the attribution object             for (prop in attribution) {                 templateString = templateString + "" + prop + ": " + attribution[prop] + "
";             }             infoTemplate.setTitle("Identify Results");             infoTemplate.setContent(templateString);             feature.setInfoTemplate(infoTemplate);             return feature;         });     });          userConfig.map.infoWindow.setFeatures([deferred]);     userConfig.map.infoWindow.show(evt.mapPoint);


Create Layer editing/Analysis in an ArcGIS web map application using Javascript API

I want to make an ArcGIS web map application in which user can select different layers of the published map (data of the layer in Postrgresql) and do some analysis based on layer data.import data to the application. Some kind of Interactive map. 1) Do I need Geodatabase or just registered postgresql database with Arcgis for Server and ArcGIs for Desktop 10.1 is enough? 2) any sample template for javascript API is available? Thank you


Tiling/Caching ArcGIS Server

A few weeks ago we crashed our server by trying to tile a large image service (600gbs) (multiple times without clearing the cache) which caused us to exceed the servers free disk space. We fixed the issue by deleting the service and clearing the server cache. From this point forward we have not been able to publish and tile an image service, however we are able to publish a regular map service. Does anyone know what might be causing us to not be able to publish/tile image services? Is there a potential break in code somewhere in a config file on the server? We are running Arc 10.1 and we have substantial free disk space. Thank you.


Layers not lining up

I have three layers I need to try match up at the borders. This is not a projection problem, all layers are projected to Albers NAD83. The base layer (Green) is 30m DEM, with a US boundaries layer on top of the DEM and finally a polygon "layer of interest" on top (Red). As you can see in the figure below, none of these layers match up at the borders. What is the best way to get these layers to match up in ArcMap 10.1? This is mainly for aesthetics, as I have it the red layer is transparent and it just looks bad. EDIT: So figure 2 (bottom) is what I have done thus far. (Note: I have changed the colors around in figure 1 just to make the different layers easier to distinguish for you all.) As you can see, the problem with the layers lining up isn't all that bad at this scale.. but I'm picky like that. Figure 1 is zoomed in to an area on the coast of South Carolina (apologies for no scale bar). @Kevin, the state boundaries were requested because this project spans many states and the hillshade (while not required) was also requested and adds some pizaz. Thanks everyone for comments so far. ![enter image description here](http://i.stack.imgur.com/KjwsJ.png) ![enter image description here](http://i.stack.imgur.com/exDbT.jpg)


Map from Mapbox as layer in OpenLayers

I want to use this map from mapbox as base layer in OpenLayers: http://mapbox.com/#/tileset/iraq I used this example to make it work. Everything is fine when I keep the code as it is with original layer "world-light", but when I change it to "iraq", it doesn't work. I checked it in Firebug and it looks fine - it asks for "iraq" tiles as the original page. Do you have any ideas how to solve it? Thanks


Standardised Spatial Information System Vocabulary

I've had some musing about this for some time and thought I'd ask the forum. _`Are there any resources out there that provide a standard, comprehensive dictionary of acronyms, terms and keywords for the Spatial Industry?`_ I've seen the Spatial Industry make leaps and bounds into other sectors outside of it's geology/geography roots, and with this terms such as GIS (geographic information system), Coordinate System, I believe are beginning to lose their potency in definition and are more historical terms due to the introduction of spatial technology to an increasing audience of users, developers and enthusiasts. The most common example I come across, is the term Coordinate System. Typically used to defined a projected and geographic coordinate system to the uninitiated, it can become confusing or add ambiguity to an answer if the merits or differences between coordinate systems is being discussed. As a result I prefer to use the term Spatial Reference System and offer the sub categories of projected reference system and geographic reference system. Essentially, I'd prefer to align myself with a set of agreed terms that can be addressed. If such a reference exists. Cheers, OptimizePrime


How do I render data quicker in Arcmap?

Is there a way around to speed up the data into ArcMap ? When I converted the raster to polygon and some data would load up quicker and some other load slow. I am wondering if I could add the spatial index to the data that load slow. Would that work ? or Is there anything that I could make the data load quicker ? Thanks


How display fields from geodata service c#

I want to display my geodata stored in the arcgis server. I did the connection to the server but the problem is the parameter versionName. I will not use arcSDE so I have ignored versionName. Can someone help me to find the solution? thx :) 'ESRI.ArcGIS.GISClient.IAGSServerObject so = GetSelectedServerProxy(); ESRI.ArcGIS.GeoDatabaseDistributed.IGeoDataServer gdso = (ESRI.ArcGIS.GeoDatabaseDistributed.IGeoDataServer)so; //++ Queries for subfields if the Get Fields checkbox is enabled ESRI.ArcGIS.Geodatabase.IQueryFilter qf = new ESRI.ArcGIS.Geodatabase.QueryFilterClass(); qf.WhereClause = ""; //++ based on the start index and count entered. ESRI.ArcGIS.Geodatabase.IResultPortionInfo range = new ESRI.ArcGIS.Geodatabase.ResultPortionInfoClass(); range.StartIndex = 0; range.Count = 500; //++ Run a tablesearch based on the version, table name, fields selected, startindex and count ESRI.ArcGIS.GeoDatabaseDistributed.IGDSQueryResultPortion res = gdso.TableSearch(versionName,"tabl", qf, range);'


Examples of geospatial scientific posters

Can you point me to examples of interesting scientific posters featuring results of geospatial analysis and/or geovisualizations?


Where can I get a world map with boundaries of regions and communities for commercial use?

I am looking for a vector file worldmap which should include as many boundaries reaching to a very small level (like ZIP-Codes/small communities/etc) as possible. The data of Natural Earth is quite good, but does not go that much in detail. The GADM data would be nearly perfect, but it is not allowed for company use. Requirements:   * Consistent boundaries for nearby countries (no overlapping!).   * As much detail as possible (refering to boundaries).   * Country boundaries and subdivisions should be separated.   * The data is for **company use** , therefore I should be able to buy it, or it should be free to use for companies. I also thought of extracting it from the OpenStreetMap data. Do you think this is possible? If this forum is not the right place for this question, please give me a hint for a better place.


make: pyuic4: command not found

I need to develop a QGIS plugin for a project. First, I launched the following command for the installation on Ubuntu 12.04:               sudo apt-get update     sudo apt-get install qgis     sudo apt-get install python-qgis      Then, I installed the **Plugin Builder** plugin. Finally, I tried to follow this simple tutorial. However, I'm stuck at the execution of the **make** command, which give to me the following error: **make: pyuic4: command not found** I did some research, but I'm unable to find a solution. Can someone help me?


Is there a way to create a plugin in C++ without compiling all the Qgis source?

This is my second post and I apologize if it's post the same day on the first. After several researchs, I found the only way to create a plugin in C++ is to compile the Qgis source with the plugin created thanks to the "plugin_builder.py" which can be found in the "src/plugins" on the git qgis (https://github.com/qgis/Quantum-GIS/tree/master/src/plugins) To create a simple plugin which can be add simply by putting the folder of the plugin in ".qgis/python/plugins" or "C:/OSGeo4W/apps/qgis/python/plugins" the plugin must be written in Python, It is rigth ? So my question is simple : Is there a way to create a plugin in C++ without compiling all the Qgis source ? Thank you very much Regards


Calculating a projected distance

I am pretty new to this and I am not sure I understand all the concepts, so I might be using words wrongly or obviously not getting some details right. Here goes. We mean to do those calculations within our program using the ArcObjects API. This is an issue related to how to use the ArcObjects API to achieve the desired result We want to do a proximity search. From a given point in projected coordinates, I want to look for objects (I think the word in ArcGIS is 'features') within a given distance given in meters (or some other real-world unit). Keep in mind here that the objects are _not_ contained in an ArcGIS database: we have the objects in projected coordinates in some other, external, list. All I want is to convert the distance from meters to a projected distance, given in projected units, whatever that is.


Allowing Add/Delete/Update of features (web application): OpenLayers + WFS and GeoServer?

I've developed a WPF application that has a custom SQL Server database and uses the Esri ArcGIS WPF API to allow users to view, edit and query shapes (features) on a custom map. Maps are created from tiles using the Bing (Quadkey) system. Users can also create multiple layers. This application has a great focus on the editing aspect. Altought I use the ArcGIS WPF API from Esri, there are no other services/servers from this company being used for this solution. Layers, features and symbols are stored using custom structures. But now I'm looking to make the transition to a web application. I've studied and tested differente mapping libraries: Leaflet, OpenLayers, Google Maps API, ArcGIS JavaScript API, etc. I know about WMS/WFS and mapping servers like GeoServer and MapServer (but I don't know what would be the best match). So, finally, my question: what would be the "best" (recommended) solution for a web application using custom (tile) maps that should have a great experience to allow users to add/delete/delete features, query, filter and save them? I know that the "best" solution can vary greatly. But what I'm really looking for is some advice from experience users that have done this. **OpenLayers + WFS and GeoServer** would be a good match? Thanks! Any help would be appreciated! :)


USGS DEM Easting and Northing metric and unit

Greetings to all! First post in here. Firstly, I am a complete noob in geography. But I have to do some programming work with DEM files. I got some DEM files from http://geobase.ca/geobase/en/find.do?produit=cded the 1:50,000 version and read in the data. According to the DEM specifications, there is a quote: > "... a 4x2 array containing the ground coordinates of the quadrangle > boundary for the DEM. The coordinates of the quadrangle corners are ordered > cloclwise direction beginning with the SW corner. The array is stored as > pairs of eastings and northings." Question: 1. Is easting and northing same as UTM metric? 2. Are UTM coordinates supposed to be written as easting-northings or northing-eastings? 3. What is the standard unit for UTM coord? meters? arc seconds? In the DEM file i have, I figured it is in arc seconds. 4. How to I convert, specifically for this DEM (see above) I have, from the "4x2" array to meters? Below is one of the DEM header data i extracted. Which this data, specifically, the SE coord (2nd line) and the 4x2 array (SW, NW, NE, SE coord) is it sufficient to point on the map where this quadrangle is? I tried very hard to map this data to google earth but i cannot seem to work out the maths.... hope someone can enlighten me. Thanks in advance!               DEM Name: 092g01DEMe     SE Coord: -12215 0.0000, 49 0 0.0000     DEM Level Code: 1     Ground Reference System: Geographic     Ground Reference Zone: 0     Ground Unit: arc_seconds     Elevation Unit: meters     Ground Resolution (lat, lng, elev): 0.75, 0.75, 1     Elavation Array Szie: 1201 x 1201     Percentage void: 0     SW Coord: -440100, 176400     NW Coord: -440100, 177300     NE Coord: -439200, 177300     SE Coord: -439200, 176400


How to create a generic tool with ModelBuilder in ArcGIS?

We are working on the creation of a tool with **model Builder** in ArcGIS 10.1. We want to build a generic tool that can be launched from any computer. In order to do so, we have set the input files as parameters in the model. When launched from the **Toolbox** , the paths on our computer come up in the parameter boxes. The user can change them, but we would like to have blank boxes instead. To do so, we delete all relative path of the parameters in the model. When we test the model in ArcMap, we get the following message “ **Error Warning 000873** ” which says that our workspace does not exist. Also we have a second kind of error: “ **ERROR 001000** ” which means that some value of zone field does not exist. **Is there anyone who has executed this operation with success and could explain us the right way of process?**


Altering composer label items in QGIS with Python

I'm only new to QGIS and Python so this may exists already, and hopefully be easy to do. What I'm hoping to do sometime in the future is build a map book generator using QGIS as the base. In order to do this I need to be able to select all the labels in the composer and replace some tags, so something like $NAME$ would replace with a variable the user has set at runtime. I have been having a look at the QGIS APIs [and source] but just can't seem to get it to do what I need. The code I have so far:               composerList = self.iface.activeComposers()     if(len(composerList) < 1):           return          composerView = composerList[0]     composition = composerView.composition()     if(composition is None):           return          for item in composition.selectedComposerItems():     //Need to check for QgsComposerLabel type and update the text.      I'm stuck when it comes to checking the type of the current item in Python, `selectedComposerItems()` just returns each item as a `QgsComposerItem` and calling `displayText()` fails because it doesn't exists on the type QgsComposerItem. I have tried the following code but it crashes QGIS when it hits a legend or scale bar:               for item in composition.selectedComposerItems():         try:             item.__class__ = qgis.core.QgsComposerLabel             if item.displayText() == "$NAME$":                 print "I found one"                 item.setText("Hello World")         except:             print "Fail"      The idea was to just try setting `__class__` on every item as `qgis.core.QgsComposerLabel` and if it throws an exception then I know it's not a label, but at the moment if it hits a legend or scale bar it crashes QGIS which is not good.


PostGIS + ArcSDE mixed environment

I'm trying out a mixed environment here at work with PostGIS and ArcSDE together. I'm having some problems creating feature classes with custom SRIDs. I imagined that all that I needed to do was update spatial_ref_sys table, but it did not worked also. Any tips on how to achive this with custom SRIDS? With normal srids it's working just fiiine. Thanks


How do you create a point at the midpoint of a polyline with Python?

I have a polyline shapfile (that contains multiple lines) and am trying to create a point at the midpoint of each line using python. I am currently using the ET Geowizards tool 'PolylineToPoints' which does exactly what I want it to...but I am trying to avoid using ET Geowizards (as it is causing other issues). Is there a way to do this in python using Arc tools and functions? Thanks a bunch!


Inaccurate result while clipping on gis data

I am trying clip polyline data using a polygon geometry. I am using itopologicaloperator to do this task. However, resultant clipped data is off by 1 feet. Meaning that the polylines at the boundaries of the polygon geometry goes beyond the boundary by 1 feet. Here is my case: 1) the polygon geometry is in GCS_North_American_1983 2) the polylines are in GCS_WGS_1984 I tried to generate the result by projecting the polygon geometry data to GCS_WGS_1984 ((I used NAD1983_To_WGS1984_5 for geographic transformation to equidistant conic projection) before clipping the data . The resultant clipped data is not accurate in that polylines cross the polygon by 1 feet or more. I tried to generate result using ESRI tools with accurate results. I do not understand why I could not do this with my code. Here is my code. Any help would be appreciated. Thanks. code:               ITopologicalOperator topo;     IFeatureCursor cursubdiv = null;     IClone geoclone = null;     IFeatureCursor curtrack = null;     IFeature feattrack = null;     IGeometry geotrack = null;     IGeoDataset geosubdiv = null;     ESRI.ArcGIS.esriSystem.IUnitConverter unitConverter = null;          //tracks are in gcs_1984     //Polygon geometry is in GCS_North_American_1983     //so convert track geometry to gcs_1984     //project clipped data to USA_Contiguous_Equidistant_Conic     try     {            geosubdiv = (IGeoDataset) psubdivftly.FeatureClass;            //get the geometry projected       geoclone = (IClone) clipgeo ;       IGeometry clipgrid = (IGeometry) geoclone.Clone();       // this polygon geometry is in GCS_North_American_1983                 ISpatialFilter spfilt = new SpatialFilter();       //project the polygon geometry to GCS_1984       clipgrid = ProjectFromEquidistantToGCS(clipgrid);                 spfilt.geometry = clipgrid       spfilt.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects       curtrack =  pGeoTrack.FeatureClass.Search(spfilt, true);            //create featurebuffer to insert clipped data into the input layer       IFeatureBuffer subdivfeatbuff =  memcliptrackly.FeatureClass.CreateFeatureBuffer();       IFeatureCursor insertcur = memcliptrackly.FeatureClass.Insert(true);            //check each feature is within or crosses and add to the virtual track layer.       while ((feattrack = curtrack.NextFeature ()) != null)       {         geotrack = feattrack.ShapeCopy;         IRelationalOperator relop = (IRelationalOperator)geotrack;         if (relop.Within(clipgrid) == true)         {           geotrack = projectFromGCSToEquidistant2(geotrack); //projects it  to USA_Contiguous_Equidistant_Conic           subdivfeatbuff.Shape = geotrack;           insertcur.InsertFeature(subdivfeatbuff);         }         else         {           if (relop.Crosses(clipgrid) == true)           {                       topo = (ITopologicalOperator)geotrack;             //get the clipped geometry             topo.Clip(clipgrid.Envelope);             // geoclone = (IClone)topo;             geotrack = projectFromGCSToEquidistant2((IGeometry)topo); //projects it  to USA_Contiguous_Equidistant_Conic             subdivfeatbuff.Shape = geotrack;             insertcur.InsertFeature(subdivfeatbuff);             }         }                 }                 insertcur.Flush();


Arcgis server not showing map service

I have a map service enabled in my server and have kml and wms as well as mapping and feature access capabilities turned on. I can view the wms in qgis, I can veiw the kml in google earth. However when I add the map as an operational layer to my config.xml in my sample application, I get no errors, the other basemap layers come up fine, and the operational layers show up in my widget (with my layer checked on), BUT it doesn't show up. I have changed my map service document to be the same coordinate system as the layer I am trying to show. The data is coming from postgresql db as an sde service. Any help would be great More info: I still have this problem. I have tried to add services that use different cs. I have reprojected my data to be the same as the basemap service in the flex sample app. I have tried to use a config.xml that only contained my service (and changed the xy extent to match. Still I can see it as wms and kml but not as a mapservice.


Run a python script every time the page is changed in Data Driven Pages? (ArcGIS 10)

I'm setting up a Data Driven Pages mapbook mxd for a series of parking locations. I have dynamic text that updates according to the current map sheet, but I also have text that needs to update using a script. I need the dynamic text to return the LotType attribute, but it is coded using a domain, so it returns an integer rather than the string associated with the integer (such as "Special Permit", "Fac/Staff", "Metered", etc). I have a VBscript from an old MPS Atlas MXD that returns the associated string, but I don't know of any way to use a script with non-MPS Atlas dynamic text. Is it possible to embed a python script into the MXD that runs whenever the user changes pages in the map book? Or is there a way to include scripts within the core Arc10 dynamic text? Thanks


How to show attributes of a new feature in Attribute table area when using IEditor3 and IEditTemplate, ArcGIS 10

ArcObjects SDK for .NET and ArcGIS 10 Desktop Quick snippet to set the stage:               IEditor3 editor.StartOperation();       IFeature newFeature;     // fill out newFeature.Shape, etc.     newFeature.Store();     editor.StopOperation("Adding new feature");      At this point I'd like to automatically "show" the attributes for this new feature in the Attribute display/table, which could be visible alongside the Create Features template list. Equivalent process through ArcMap itself:   * Start the Editor via the Editor Toolbar.   * Click a feature template from the **Create Features** list.   * Click the **Attributes** button to open the Attributes display.   * Mouse-down in ArcMap. See new/default attributes for the new feature be displayed in the Attributes table area. Is the possible with ArcObjects for .NET?


How to filter layer of osm data?

I have a table osm_roads that has a column named _geometry_ geometry geometry(LineString,900913). If I want to filter a city to draw districts, I cannot do it by geographic coordinates? What if in openJUMP or QGIS I want to select by bounding box, such a table as that? Thank you in advance.


How to convert GDB data to shapefiles without ArcGIS?

We've got some data (supposedly it's a simple collection of points--or at least that is all we need to extract) from a 3rd party in a GDB folder (I don't know how to tell what version) but we don't have an ESRI Arc* product. We are not primarily a GIS company, and our tools basically support only shapefiles. How can we convert the GDB to shapefiles? Note: I tried following the instructions to get GDB support in QGIS (after uninstalling QGIS and re-installing via osgeo4w-setup) but it didn't work; QGIS still says "Xyz.GDB is not a valid or recognized data source".


references for the colloquial naming of spatial data resolution

In our era of data deluge, many folks, including myself, quest for ill-defined "high-resolution" datasets. I suspect that colloquial description of spatial resolution as "high" or "low" is and will continue to be a set of terms relative to the what was available in the recent past. However, I'm wondering: are there peer-reviewed conventions for subjective description of spatial resolution? Perhaps some sort of Beaufort scale for spatial resolution?


What tool do I need to have satellite background images to draw features of a postgis database? I looked about Geomajas but seems very complex for what I'm trying to do. I have osm data imported in a postgis database, as a layer in QGIS. The second layer is what I am drawing, and the third layer that I ask here is how to have satellite imaginery on bottom of the two mentioned ones as a visual aid in drawing features.