Digital Elevation Model Fusion

I want to fuse Digital elevation Models extracted from Carto-1 satellite. I already extracted DEMs & tried few algorithms in Matlab. Unfortunately as they are not Georeferenced i am not getting accurate results. So is their any tool or model which can use for Georeferencing & fusing DEMs?


How to use %value% (from For iterator) in SQL expression of Calculate Field in ModelBuilder?

I have a shapefile with data of fish specimens and the coordinates where they were tagged for research purposes. One of the fields in the attribute table of these shapefiles is the fish length in centimeters (ReLenCM). I am building a model that will create three new fields in the shapefile with weight values calculated with three different estimations of the length-weight relationship for that species. To make my enquire simpler, instead of using those functions yet I´m trying to just have the length value multiplied by an iteration. My For iterator is From 2, to 4, by 1. Meaning my three iterations are 2, 3 and 4. Therefore, for instance for the first row in the table (see pic) I am aiming to have something like this: ReLenCM = 79; W_2 = 158; W_3 = 237; W_4 = 316 This is the configuration of the **ArcGIS 10.1 for Desktop** model: ADD FIELD:   * Field Name_Add = W_%value% (resulting in W_2, W_3 and W_4)   * Field type = Double   * Input table = Model parameter (shp of tagged fish releases) CALCULATE FIELD   * FieldName = %Field Name_Add% (not entirely sure about this one)   * Expression = Here is where I want to multiply length by each of the iterations. You can see my attempt in the picture ([ReLenCM] * [W_%value%]), but with that expression all I get are "0" values... Basically, I just need to know how to insert the %value% variable from the iterator in the SQL expression. I have found some posts describing a similar issue, but always with String variables, not numeric. ![Model diagram](http://i.stack.imgur.com/a38sT.png)


Matching GPS tracks

I'm looking for a proper way to **process multiple GPS tracks** (so time ordered list of lat/lon points) and match/classify that segments, that are covered by multiple tracks: ![enter image description here](http://i.stack.imgur.com/WCygS.png) So it's not about recording, but using known algorithms/open source to do the analysis.   Sadly I didn't found a ready-to-use solution at the web, just scientific conceptual papers. My ideas would be:   * use spatial index to scan just in point subsets (but what with points at borders?)   * scan point sets with a buffer (to skip accuracy jitter)   * classify points that sit in the buffer But I like to have a real processing that is known to work. I guess this is a very common requirement to fleet monitoring solutions, so there must be some existing solutions that I just don't know :/   Can anyone suggest an existing tool (in QGIS or via a Python lib) that can do this matching? _BTW: Happy new year 2014 to all GIS and SE folks :)_


How to import label classes to make symbology classes?

In Answer to an earlier Question I was able to write SQL Expressions to create label classes. Now, I wish to use those label classes to create symbology classes. It is possible to make label classes from symbology classes, but I want to do it the other way around.


ArcPy Result Object Associated with Currently Running Script

We are at the end of a Python script using ArcPy. We can crawl around ArcPy to get information, but is there any way to get a result object for our currently running script? My motivation is to use existing code to process the same result object we might get from executing a separate script tool earlier in the script. To clarify, I want this object: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Result/000v000000n7000000/ I was wishing I could get a Result object for the currently running process. Here are my notes for accessing ArcPy instead:               #Result.inputCount and Result.outputCount     outParameters = []     inParameters = []     for parameter in arcpy.GetParameterInfo:         if parameter.direction == "Input":  #unsure of exact string             inParameters.append(parameter)         else:             outParameters.append(parameter          inputCount = len(inParameters)       outputCount = len(outParameters)           #Result.MaxSeverity     maxSeverity = arcpy.GetMaxSeverity()           #Result.MessageCount     messageCount = arcpy.GetMessageCount()


ArcObjects ISQLSyntax with Oracle DB esriSQL_DelimitedIdentifierPrefix issue

New to stack exchange, heading over from the esri forums, it is great! I am trying to produce a query that I can use across all workspaces, naturally using ISQLSyntax. The problem I'm having is that when using esriSQL_DelimitedIdentifierPrefix on a Oracle SDE instance it is returning a speech mark, whereas I'd expect it to return a blank string. When I use this code on a FileGDB or an MDB it works as expected, but on SDE I get the error: Underlying DBMS error[ORA-00904: "table.field_name": invalid identifier][OWNER.TABLE] The error goes away if I remove the prefix and suffix, so there are no typos in the query. I don't want to do a select case SDE because it seems against the point of having ISQLSyntax. Any Ideas?               Dim Prefix As string, Suffix As string     Dim upper As String, sQualColName As String     Prefix = pSQLSyntax.GetSpecialCharacter(esriSQLSpecialCharacters.esriSQL_DelimitedIdentifierPrefix)     Suffix = pSQLSyntax.GetSpecialCharacter(esriSQLSpecialCharacters.esriSQL_DelimitedIdentifierSuffix)          sQualColName = pSQLSyntax.QualifyColumnName("table", "field_name")          sVal = Prefix & sQualColName & Suffix & " = " & Chr(39) & Trim(strFindString).ToUpper & Chr(39)


Merge long/lat points within a bounding box depending on a radius in MySQL

Here is a pic of what I basically want to achieve: http://i.stack.imgur.com/gjbfa.png So as the title says, I want to merge long/lat points which they're radius (of 25Kms for example) touch inside a bounding box of long/lat points. Here is my very simple DB structure:               +-------+-------------+------------+     | id    |        long |        lat |     +-------+-------------+------------+     |     1 |   -90.27137 |   50.00702 |     |     2 |   -92.27137 |   52.00702 |     |     3 |   -87.27137 |   48.00702 |     |     4 |   -91.27137 |   51.00702 |     +-------+-------------+------------+      Here is my query so far:               set @bottom_lat = -100.27137;     set @bottom_lon = 40.00702;          set @top_lat = -80.27137 ;     set @top_lon = 60.00702 ;     ;          SELECT AVG(latitude), AVG(longitude)     FROM destination     WHERE latitude > @bottom_lat AND longitude > @bottom_lon AND latitude < @top_lat AND longitude < @top_lon      So my query just merging all points inside an imaginary bounding box without considering radius. I know that I would prorably have to work with the Haversine formula but I'm crap at maths and MySQL which make things a little bit difficult. Indeed, I could eventually merge points if I had just one radius but each points have its own radius and I'm struggling. This is for a student project and any help will be much much apreciated. References: -My query on SQL Fiddle: http://sqlfiddle.com/#!2/3a42b/2 ( contains a SQL Fiddle exemple for the Haversine Formula in comment ) -The Haversine formula in MySQL query: (work for checking all points inside a given radius)               SELECT*, ( 6371* acos( cos( radians(     @my_lat) ) * cos( radians(      destination.latitude ) ) * cos( radians(      destination.longitude ) - radians(     @my_lon) ) + sin( radians(     @my_lat) ) * sin( radians(      destination.latitude ) ) ) ) AS distance      FROM destination     ORDER BY distance limit 1     ;


Create ERDAS IMG Statistics using GDAL C++ API?

I want to create very many ERDAS .img files using GDAL under C++. I don't want to have to process them all in ArcMap to create statistics for them (mainly because ArcMap fumbles when calculating statistics for very many input images in batch mode). I want to create the .img files complete with statistics calculated for each. I see python utilities for this, but nothing under the C++ API. Does anyone have a solution?


What is difference between GeoTIFF and Esri ASCII grid file formats for SRTM data?

what is the difference between the ArcInfo ASCII format and the geotiff file format when downloading the SRTM data. I downloaded the tiles (21) for the Tibetan Plateau and imported thme into ArcMap 10. It looks quite different. The ArcInfo ASCII looks like a puzzle and the geotiff ones are very grey... but no puzzle. Has anyone an idea?


Using field calculator to delete specific contours

I have 3 contour shapefiles with 25m, 50m and 100m equidistance. Now I want to delete in the 25m-shp-file every **50m and **00m contour and in the 50m-shp- file every **00 contour. How can I show them using the field calculator of qgis? Thanks!


GeoServer and OpenLayers in production - Securing WMS calls?

I've a mapping site where users have to login in with username and password. Once logged in the user gets a map of their data using WMS and WFS to display and edit data. This data is served using GeoServer and displayed using OpenLayers. The WMS on the layer is secured using a username\password. I've seen similar questions to this but basically I want to access the secured layers via WMS without exposing my username\password. Any advice\clarity would be appreciated - my own thoughts are as follows:   1. User logs in to website.    2. WMS request using HTTPS for their specific information - uses some filter based upon who they are.   3. How do I send this filter without exposing it in the WMS call?   4. How do I send username\password without exposing it in WMS call? Theres lots of talk about reverse proxies - do I send the WMS request with no username\password then when the request reaches the proxy I validate the user then modify the request by adding the WMS username\password using the reverse proxy. If so dont I still need to send some identifier to determine who sent the request or will the proxy knows this due to the users session? Basically any help would be appreciated


How to store attributes of a large shapefile in a list?

I am trying to store the attributes of a shapefile into a list. With following code it works for smaller shapes:               addA = []     While provider.nextFeature(feat):         attrs = feat.attributeMap()         for (k,attr) in attrs.iteritems():             addA.append(attr.toString())      If I try to store a large shape my pc runs out of memory or freezes. I tried to put the attributes in a blist and in a numpy array, but nothing really worked (or probably I did not understand how to set up a proper numpy array...). Is there a solution for this problem?


Set a Required Field in QGIS Edit Form

Is it possible to make a field required in a QGIS Edit Form?


Which is better for tiling: raster2pgsql or GeoWebCache?

We have some raster image data stored as GeoTIFF which we would like to make available online as an overlay using the OpenGeo framework. As the data covers only a spatially restricted area and we don't need too much zoom levels, we consider precomputing ("seeding") the tiles as applicable with respect to memory consumption. Using OpenGeo, there seem to be two modules which can handle tiling:   1. raster2pgsql: a command line tool which converts a raster file into a series of SQL commands that can be loaded into postGIS. It offers the option to specify the tile size and the zoom levels (in their syntax "overviews")   2. GeoWebCache: assists GeoWebServer with cache functionality and tile generation. The latter can be done prior to client requests or on the fly. I'm not sure about how the two differ with respect to the precomputed tiles, can anybody clarify this? At first glance I tend to GeoWebCache because of the convenient access through its web interface.


Is it possible to put Geoserver behind a proxy and access the WMS/WFS using OpenLayers

I just start to work with Geoserver and Openlayers and one of the main concerns of the project now is do not expose the geoserver web interface outside of the internal network. No access to www.mydomain.com/geoserver/ However the application that is available in the Internet needs to get data (wms/wfs) from the Geoserver. This all through OpenLayers. Is this possible? Thank you all


Handle add new feature event and/or access feature before commit?

Is it possible with PyQGIS to catch "add new feature" event before commiting changes on the layer? or at least to access new features before commit.


ASTER mineral indices with VINR and SWIR data

I need to run a supervised classification on ASTER data in order to map a rock formation, which is composed of chert. There is no shortage of indices which can be used to highlight silica rich formations, see http://www.ga.gov.au/image_cache/GA7833.pdf. However, all of the indices I have found thus far utilize the TIR bands, which have a spatial resolution of 90m, and I need to map at a much finer scale than this permits. The either of the the 30m and 15m resolutions of SWIR and VNIR respectively should suffice. The problem is that I can't find any silica indices which use these bands. I understand that any such indices might be sub optimal in comparison to those which use the TIR bands, but in this case resolution is of uptmost importance. So, the question is; does anyone know of any established chert/silica indices which use the VNIR or SWIR bands?


What is best way to reorganize osm into PostGIS database entity?

I'm just wondering how to reorganize the OSM given entity to more flexible and schematic purpose. The OSM gave 4 entities the planet_osm_line, planet_osm_point, planet_osm_polygon and planet_osm_roads. Is there a good practice to reorganize them like into city_building, city_road and etc. I'll be reorganizing a city's spatial objects. Thank you in advance


Generating polygons with shared boundaries using QGIS?

Essentially the problem is that if you digitise each polygon separately the boundaries will not match exactly. My instinct is to have a table of line segments and generate the polygons from that using postgis but then all the line segment end points have to join exactly which is painful as there are a lot of line segments. I have thought about writing a script that uses heuristics to match up lines and then add extra segments to bridge the gaps as suggested in a previous question I asked: How to automatically convert line features into polygons using QGIS/PostGIS? I feel this is such a common task that there must be some "best practice". If I were starting from scratch then how would I do it?


Batch fix overlap errors

I have a feature class with about 250,000 contiguous polygons. ArcEditor turns up around 9,000 overlap errors when I validate the topology. I want to merge each of these errors into one of the polygons they source from - they're all very tiny overlaps, so it really doesn't matter which one. All 9,000 errors can be fixed in exactly the same way. In the Error Inspector, the Merge option is only available when I select one error at a time - selecting a bunch of them greys it out. This means I need to do the same repetitive task for every single error. I would love to be able to avoid doing these one at a time, might save me from carpal tunnel and wasting the better part of a day. Any suggestions?


Clipping points using buffer in Arcmap takes FOREVER

I'm clipping points (crimes) by using a buffer around a shapefile of city parks. There are quite a few records involved (2 million+), but it is still taking forever - as of now, the clip has been running for an hour and ten minutes. I'm also using a subset of the parks data, so I'm not clipping crimes with every polygon in the shapefile. My questions: How does Arcmap go about it's clipping? Does it have to check every point, even those that are nowhere near the polygons? Is there a better method? I have QGIS at home, but I'm not sure if it's as fast as Arcmap. Thanks, Ward


How to hide infoWindow while using measure tool and showing it back after using it ArcGis JavaScript API

I have an infoWinfow set on the click event of the map. I want to disable this event when I'm using the measurement tool and then enable it back after the measurement tool is used. So far I've done this code, where the click event for the infoWindow is disable when the measurement tool is used. I want to enable the click event back after the measurement tool is used. Any ideas on how this could be done? Thanks.               function initToolbar(mymap) {     var measurement = new esri.dijit.Measurement({         map: mymap     }, dojo.byId('measurementDiv'));     measurement.startup();     measurement.setTool("area", false);          measurement.areaToggleButton = function () {         this.clearResult();         this.setTool("area");         dojo.disconnect(clickHandler);     };     measurement.distanceToggleButton= function () {         this.clearResult();         this.setTool("distance");         dojo.disconnect(clickHandler);     };     }


How to remove polygons in shapefile based on attributes in R

I have a shapefile where some attribute data is blank. I can delete those rows attribute table using na.omit. However, the polygons remain when I map the shapefile. I'm using R to make these changes. My shapefile contains over 900 records/polygons and 450 of these records have NO attribute information attached. These 450 are the ones that I want to remove. In the example, below I will need to remove both the shape and the record of ID:4.               For example:     ID Attribute1 Attribute2     1     data       data     2     data       data     3     data       data     4      NA         NA      How do I go about removing these shapes in R? Thanks for your help.


ArcGIS 10.1 SP 1 install on Windows Server 2012 questions

I will be setting up ArcGIS server 10.1 SP 1soon and I have a few questions before I start this. I have looked at the Web Adapter and the ArcGIS install guides but wanted to get some input. 1.Has anyone been installing on Windows Server 2012? I will be installing ArcGIS 10.1 SP1 and the Web Adapter on a separate 2012 servers. Have there been any problems with this that people have ran into? Should I just stick with 2008 R2 or just go with 2012? 2.I see the ArcGIS server needs IE 7 min, and looks like it can go up to 9. Will this software work with IE 10 though? 3.What ports am I going to need open between the Web Adapter server and the ArcGIS server, 6443? Is 6080 just for the server to World if I am doing the web and GIS all on 1 server? 4.If I am using SSL and HTTPS over port 6443, should I be using certs?


3D elements buffer extrusion

I'm using ArcScene10.1 and I have a dataset containing of 3D points (x,y,z coordinates) with extrusion values (Evalue). Now I would like to create a square or ring buffer around the points and extrude that buffer by the extrusion value. The goal is to "layer 3D to feature class" those geometries and colour them by an other value (Cvalue). So far I was able to create a buffer around those points but I can't extrude them. eg.:               x y z Evalue Cvalue     1 2 3 5       3     2 4 1 3       15      ... ![draft](http://img594.imageshack.us/img594/741/extrudebufferdraft.jpg)


Get raster expression

In Arcmap I have made a new raster with ArcToolBox -> Spatial Analyst Tools -> Map Algebra -> raster calculator. Now, months later, I have forgotten the source formula expression. How can I display?


PostGIS Trigger doesn't work

The trigger below don't works and I need that when a new pipeline (adutoras) is inserted or updated, the procedure check what are the municipalities (municipios) that intersects the pipes and put the names of the municipalities inside the field "municipios_abastecidos".               CREATE OR REPLACE FUNCTION topology_fields()      RETURNS "trigger" AS     $$     BEGIN     NEW.municipios_abastecidos:=(                           SELECT string_agg(municipios.nome,', ')                           FROM municipios, adutoras                           WHERE ST_Intersects(adutoras.geom, municipios.geom)                           AND adutoras.gid = NEW.gid                         );     RETURN NEW;     END;      $$     LANGUAGE 'plpgsql';               CREATE TRIGGER fill_topology_fields     BEFORE INSERT OR UPDATE ON adutoras     FOR EACH ROW EXECUTE PROCEDURE topology_fields();      Thanks in Advance


leaflet fitBounds with multiple marker

I have created two checkboxes. If I check one it will zoom to a point with marker. If I uncheck the checkbox the marker removed. Similarly second one is working. But I want to do if the two checkboxes are checked at a time it will zoom at a position where both are visible. Again when one of it checkbox is unchecked it will zoom to the points best fit position. I know that fitbounds can solve this but couldn't imliment it. Here is my code I used. Any suggestion will be a great help. Thanks               <input type="checkbox" name="One" id="one" >One</input>

<input type="checkbox" name="Two" id="two">Two</input>
           $('#one').click(function(){          if($("#one").prop('checked') === true) {              var marker = L.marker([32.304255,-64.752098]).addTo(map).bindPopup('One');              map.setView(new L.LatLng(32.304255,-64.752098), 16);              marker.on('dblclick', function(){              marker.openPopup();              });          }      });      $('#two').click(function(){          if (this.checked) {              var marker= L.marker([32.319343,-64.728066]).addTo(map).bindPopup('Two');              map.setView(new L.LatLng(32.319343,-64.728066), 16);              marker.on('dblclick', function(){              marker.openPopup();              });           }      });          var xLayer =[];     function clearLayer(){     for(var i =0; i < xLayer.length; i++)         map.removeLayer(xLayer[i]);         xLayer = [];     };          $('#one').click(function(){         if($("#one").prop('checked') === false) {         clearLayer();         }     });     $('#two').click(function(){         if($("#two").prop('checked') === false) {         clearLayer();         }     });


Creating seperate layers out of one big polygon shape by using attributes

I try to explain may problem. I have a big polygon shape (> 200 fields). I have the owners of these fields in a column. I need the seperated shapes for each owner. Is there a tool to do that? Is it also possible to get an information about the whole area? Like a summary: 201 polygones area: 1450 ha In Saga I have a tool "Split shapes by attribute". This works fine with the expected result (10 owners: 10 new layers). This tool doesnt work with the sextante plugin. Thanx!


field calculation in arcgis

* i have a data which contain a code of area an value of area in shapefile, ex.: area|value   1|33   1|43   1|31   2|12   2|43   3|66   3|76   the question is how to calculate total value per area with arcgis, i heve been tried with arcgis calculator and it doesnt work? what i expect for result is      area|value|total   1|33|107   1|43|107   1|31|107   2|12|55   2|43|55   3|66|142   3|76|142


Working with ambiguous AddGeometryColumn functions

I'm using PostGIS to add geometry columns to tables, but keep receiving the error:               ERROR: function addgeometrycolumn(character varying, character varying, integer, character varying, integer) is not unique     SQL state: 42725     Hint: Could not choose a best candidate function. You might need to add explicit type casts.      The statement I am trying to call is: SELECT addGeometryColumn('schema', 'table', 'geom', 3857, 'POINT', 2); I have tried type-casting each argument but I received the same message. I have also removed and re-installed the postgis extension, which made no difference. I have used this function countless times before and am somewhat puzzled as to why it isn't working all of a sudden. I have also tried a few other postgis functions which gave me similar errors. I am considering reinstalling postgresql/postgis but I will have to spend time reconfiguring the set-up so I am hoping there is an easier way to fix/get around this. Does anybody have any advice as to what may be causing this? Thanks in advance


Looking for PyQGIS Syntax Examples/Guide

I am a long-time user of arcgis with intermediate experience python scripting for automation of geoprocessing workflows. I am moving towards using QGIS on the regular and I would like to dive into python scripting for QGIS. However, I have previously relied on esri's help screens which contain python syntax as well as examples (ESRI Example). Is there an equivalent of this python documentation for QGIS? I have found the PyQgis Cookbook limited and the API Documentation beyond what I'm able to undertake. Any suggestions would be much appreciated. thanks in advance, mike


Census Demographic Data from DMA ID

How can I go about finding demographic data by DMA ID? Is there a data file I can download from somewhere that I can use to import into my web application?


Making Tiles - Varying the Zoom Level by Population Density

I want to create map tiles for all of the United States at high zoom level (12 or 13). I am using TileMill and mapping census tracts (income). However, I only need the high zoom level for populated areas. How could I exclude the areas with low population? I want to do this to minimize tile generation time and webhost disk space. For instance, I'm going to treat Alaska separately as most of it has low population density. I can also exclude oceans and large lakes. I could probably exclude a large portion of WY, ND, SD, and several other western states.


joining polygons

I am wondering how to join spatial polygons using R code ? I'm working with census data where certain areas change over time and I wish to join the polygons and the corresponding data and simply report on the joined areas. I am maintaining a list of polygons that have changes census to census and that I plan to merge. I'd like to use this list of area names as a look up list to apply to census data from different years. I'm wondering what r function to use to merge selected polygons and respective data. I ahve googled it but simply become confused by results. Hoping you all can help :)


Insert into X coordinate separately?

I have a postgis table with a point geometry for lat/long but i want to run a query that inserts a new row with lat, long values separately instead of concatenating them into a geometry. so is there a way to insert the X and Y values separately ?


Arcobjects: DisplayTransformation.FromMapPoint() transforms wrong

I want to transform map coords into page coords in ArcObjects in Python. So I do, say:               >>> pApp = NewObj(esriFrame.AppROT, esriFrame.IAppROT).Item(0)     >>> pDoc = pApp.Document     >>> pMxDoc = CType(pDoc, esriMapUI.IMxDocument)          >>> pDisplay = pMxDoc.ActiveView.ScreenDisplay # something wrong here?     >>> pDisTrans = pDisplay.DisplayTransformation          >>> pageX, pageY = pDisTrans.FromMapPoint(ptInRealCoords) # coords are ~389700,~316671m     >>> pageX     6523059 # which should be ~4.73 in cm      Any clues whats wrong?


Openlayers Linestring over edge of map

im trying to create a route displayer for ships. But im struggling with the edges of the map. When going from ie. 179* to 2* it displays a line across the entire map, instead of displaying it on the continuation of the map. (Map repeats) I do see why it would do that. But i was hoping there was some support in openlayers for making this more or less automatic instead of breaking up the route. Any ideas on how to fix this? **Expecation:** ![Expectation](http://i.stack.imgur.com/1ttwm.png) **Current display:** ![Current display](http://i.stack.imgur.com/PH5J9.png)


Find end of arc given start/end angles, start point and radius

Using PostGIS, how do I work out the end point of an arc given the start point, start and end bearings (relative to true north) and radius of the arc? Eg. say I need draw an arc of 4000m radius from bearing 180 degrees to 90 degrees with the start (the 180 degree point) at POINT(10 20). How do I calculate the end point (other than approximately drawing the arc, point by point)? This is only for short distances, so working on a plane should be OK. I can work out the distance between the start and end point using the length of chord formula and if I could just get the bearing between them as well then I could use ST_Project - but I don't know how to work out the bearing. (In the simple example above it should be 45 degrees.) **Solution:** It ended up being quite simple in the end. Thanks to **whuber** for explaining it very well. I wanted to put the PostGIS code here in case anyone else wants it:               centre_point := ST_Project(start_point, radius_m, normalise_angle(start_angle + pi() / 2 * CASE WHEN is_clockwise THEN 1 ELSE -1 END));     end_point := ST_Project(centre_point, radius_m, normalise_angle(end_angle + pi() / 2 * CASE WHEN is_clockwise THEN -1 ELSE 1 END));      `normalise_angle` is a simple function that ensures the angle is between 0 and 2PI (as required for ST_Project), `start_point` is a `geography(Point)` and `radius_m` is the radius in metres. Angles are in radians.


Create a color scale/legend for choropleth map using geotools (or other open source Java library)?

I'm experimenting with choropleth maps using geotools. Is there an easy way to add a color scale to the map (using geotools itself or some other os library)? By a color scale I mean a bar that shows how the feature attribute values map to color, with labeled ticks either automatically generated, or at break points of my choosing. Ideally, I'd like to generate a separate color scale that could be rendered independently of the choropleth map, so that I can use a single color with layouts containing multiple maps. I'm not absolutely wedded to geotools, and would consider other open source libraries, though I'd much prefer to stick with JVM languages (Clojure, Groovy, Java, ...).


Map source for iLife '11?

The new iLife has map functionality, what's the source of the map data used? ![ilife map image](http://i.stack.imgur.com/KoMRU.jpg) Further pictures on engadget, which show a city-level view.


Is there a geodetic benchmark that is fixed with respect to plate tectonics?

I see that NGS benchmarks are used to monitor the movement of geologic plates. Is one of the benchmarks assumed to be in a fixed location, with movements of all other benchmarks measured with respect to it, or are all benchmarks moving as a result of plate tectonics?


geopandas error when writing to_file() "ValueError: 'long' is not in list"

I'm having a problem getting the "to_file()" function to work with geopandas               import geopandas as gpd     f  = gpd.read_file('fin.shp')     f.to_file('fout.shp')      Error Output:                   ---------------------------------------------------------------------------      ValueError                                Traceback (most recent call last)     <ipython-input-14-6fdee04dae37> in <module>()           1 f  = gpd.read_file('fin.shp')     ----> 2 f.to_file('fout.shp')          C:\Python27\lib\site-packages\geopandas-0.1.0.dev-py2.7.egg\geopandas\geodataframe.pyc in to_file(self, filename, driver, **kwargs)         308         filename = os.path.abspath(os.path.expanduser(filename))         309         with fiona.open(filename, 'w', driver=driver, crs=self.crs,      --> 310                         schema=schema, **kwargs) as c:         311             for i, row in self.iterrows():         312                 c.write(feature(i, row))          C:\Python27\lib\site-packages\fiona\__init__.pyc in open(path, mode, driver, schema, crs, encoding, layer, vfs)         154         c = Collection(path, mode,          155                 crs=crs, driver=driver, schema=this_schema,     --> 156                 encoding=encoding, layer=layer, vsi=vsi, archive=archive)         157     else:         158         raise ValueError(          C:\Python27\lib\site-packages\fiona\collection.pyc in __init__(self, path, mode, driver, schema, crs, encoding, layer, vsi, archive, **kwargs)         129             self.encoding = encoding         130             self.session = WritingSession()     --> 131             self.session.start(self, **kwargs)         132             self.encoding = encoding or self.session.get_fileencoding().lower()         133           C:\Python27\lib\site-packages\fiona\ogrext.pyd in fiona.ogrext.WritingSession.start (src/fiona/ogrext.c:15304)()          ValueError: 'long' is not in list      I'm using fiona 1.1.3 and geopandas 0.1 with Python 2.7 on Windows. It may be a problem with my ogrext.pyd dll in fiona - any help is much appreciated


How to use ISymbol QueryBoundary

I have a balloon callout ISymbol and I want to get a polygon object so I can see if the user clicks it. I am trying to use the function QueryBoundary http://help.arcgis.com/en/sdk/10.0/arcobjects_net/componenthelp/index.html#//001w00000372000000 The function has four arguments:               public void QueryBoundary (         int hDC,         ITransformation displayTransform,         IGeometry Geometry,  //what can I put in here?         IPolygon boundary     );      One of my major hangups with the third argument is simply the fact that I am using this function to try to get the geometry... so what sense does it make to pass in the thing that I want? Also since the function is called like this :               thissymbol.QueryBoundary(screenDisplay.hDC, displayTransformation, thisGeometry, polygon);      Presumably it doesn't need the geometry of "thissymbol" since "thissymbol" is the caller.


which is the suitable Geographical Coordinate System and Projected Coordinate System for India

I want to create a spatial data for entire India, usually I use WGS84 as GCS and UTM zones for PCS in the places in India, but when I have to create the spatial data for entire India, I get confuse which geographical coordinate systems and projected coordinate system will be suitable for India, please help me to identify the suitable one and explain me why it is suitable.


How to return end of string up to a certain character using Field Calculator?

I am trying to accomplish this task: http://stackoverflow.com/questions/15851568/how-to-get-the-last-part-of-a- string-before-a-certain-character within the Field Calculator. I have the below but cannot get it to run. What am I missing? Any suggestions or assistance would be much appreciated. ![enter image description here](http://i.stack.imgur.com/sMxbT.jpg)


Obtaining a handle for newly created map in GeoExt

Hopefully a straightforward question... I am following the example based on this page here http://www.geoext.org/lib/GeoExt/widgets/MapPanel.html to create a map within a window, here's my code:               new Ext.Window({         title: "GeoExt MapPanel Window",         height: 400,         width: 600,         layout: "fit",         items: [{             xtype: "gx_mappanel",             id: "mappanel",             layers: [basemap],             extent: "-5,35,15,55"         }]     }).show();      So the above example create a new map in a floating window which is exactly what I'm after... My question is how exactly do I get a handle to the map within this new window so I can add controls and layers after the map has been created? Something along the lines of:               map = grab_the_map_somehow_from_Ext.Window_above();     map.addControl(my_new_control);     map.addLayers([my_new_layer]);      Thanks for your help.


Spatially join polygons (target) to polylines (join) on longest intersecting polyline

I am curious if I can, without having to write a python or an ArcObjects script, create a spatial join that will result in a polygon feature class containing the attributes of the LONGEST intersecting join polylines. The input polylines I have roughly correspond to the polygons to which I want to transfer the attributes. I've determined that it is almost always the longest intersecting polyline whose attribute I need to transfer into the polygon. Currently, using the figure below as an example, the spatial join hits 3 polylines (join_count = 3 for this particular polygon) but instead of joining on the longest intersecting polyline it seems to choose the first one it encounters. (which is also contrary to what the tool's description says about the JOIN_ONE_TO_ONE operation which is suppose to aggregate the join features into the output feature. The description speaks of SUM merge rule in its example which I do not see in this particular tool as an option) I am using INTERSECT because there is no suitable spatial relationship I can think of in this "polyline to polygon" situation. I understand what is going on but don't know whether a workaround exists. I just wish there would be another set sub-parameters allow me to control what happens when more than one join features exists; in this case selecting the longest polyline by default. I am using ArcGIS 10.2.1 Standard. ![enter image description here](http://i.stack.imgur.com/ESjIZ.jpg)


Display linestring on Cartodb with SQL

I have a Cartodb api for a separate map, I need to display a linestring for each time the sql is run, but not store the linestring in the database.


Which kind of grid format is this?

in a project I got some raster files with the following content (header and data are in one txt file):               HOUR 17     MINUTES 30     YEAR 2012     MONTH 5     DAY 4     CITY Emilia;Bologna     NROWS 99     NCOLS 156     ULXMAP 11.2087224106     ULYMAP 44.5539582648     XDIM 0.0016666668     YDIM 0.0012500001     CELLE_TRUE 2999     CELLE_FALSE 1     0.15478748  0.15478748  0.15478748  0.15478748  0.15478748       0.15478748  0.15478748  0.15478748  0.15478748  0.15478748       0.15478748  0.15478748  0.077375025 0.018038042 0.01576243     [...]      I tried to identify the format but did not get far. It seems to be a "kind of" ESRI ASCII grid, but it features non-square pixels (as you can see), which is not supported by ESRI ASCII grid (AFAIK). It might be an Arc Grid format (I found this link: http://landcover.usgs.gov/faq_importing_arc.php) but then I am lost. GDAL does not recognize the format, QGIS and ArcGIS 10 don't like the format either. Does anybody know this particular format (coming from an Italian source)? Or give me a hint how to process it to an more "readable" format? Regards and thanks in advance Jan


Accented characters in csv file appear as '?' when importing to QGIS

The tabular data (.csv file) and the data in the attributes table of the vector (.shp file) I am trying to join includes accented characters - they are place names in Pamana. For example 'Río Abajo' and 'Curundú'. The problem is that when I import the csv file as a vector file QGIS can't seem to read the accented characters and puts a little '?' instead for those characters. So I just get NULL values appearing in the joined attributes table - all the data for the unaccented names turns up perfectly. I have tried changing the names to unaccented latin characters, from the earlier example 'Río Abajo' becomes 'Rio Abajo'. But then the names don't match up with the place names already in the attributes table of the shapefile I am using (administrative areas for Panama) so the NULL values appear again. Hope you can help.


Fw tools using error

I am using Fw tools. And I am writting cmd screen:               ogr2ogr -f \"GeoJSON\" -t_srs WGS84  D:\\electric_Data1\\direk.json  D:\\electric_Data1\\ag_direk.TAB      tried. And I have a error. error code:               unable to find driver '"GeoJSON"'      The following drivers are avaible:           esri shape file     mapinfo file     bla bla bla     GeoJSON     bla bla bla


"Easy Custom Labeling" arrows: How do I get them?

I have installed the Easy Custom Labeling plugin, but haven't figured out how to make the "Generate lines" function work. When I click on the tool in the toolbar, it opens the dialogue to specify my CRS. Ok, that's done. So having moved a label that was too crowded, how do I make the connector line? THANKS TVZ (I'm running QGIS 1.8)


Save Multiple Selection from Attribute Table

I am working with a shapefile that has all the address points for a municipality - it has over 500,000 features. I would like to search the attribute table for specific addresses and save those somehow so I can sort and only show the ones I want - likely around 1000. After searching for one property I can move it to the top of the list, but when I search for the next and move it to the top, it replaces my first result. How can I flag or select a series of search results and then only save those in my attribute table? P.S. I am using QGIS v. 2.4 Thanks!


Class Probability Tool in ArcGIS Desktop 10.2

I am trying to create a multi-band raster using the class probability tool in ArGIS Desktop 10.2. I used the classified image I created based on my signature file as the input raster, and my training classes (.gsg) extention as my input signature file. All I get as an output when the tool runs is a mostly grey layer with no actual information attached to it. Anyone have any ideas about what I am doing wrong.


Any way to view/create/edit Google My Maps KML files on Android?

I have two large (several hundred features) maps created by Google My Maps that I use for my field research. They contain important information required by the field crew for their work on site. Currently these maps are accessed via iPhone by using a free app called My Maps Editor. This allows each individual to view all the features as well as create and edit new features as needed, that the rest of the crew will view. However, I have been wanting to switch from iPhone to Android for a very long time. Currently the ONLY thing holding me back is that I can't get the same functionality on Android that I can on Iphone. Yes, Google's native maps and Google Earth apps allow you to VIEW the My Maps, but there are several limitations which make this essentially useless. What I need is to be able to:   * View multiple maps overlaid (Google only shows one at a time)   * View ALL features on each map (Google caps off at around 200 and arbitrarily decides which ones to show)   * View and edit these features (Google does not match the names with the features, and does not allow existing features to be edited). Is anyone aware of an app that allows this on Android? Alternatively, is anyone aware of another strategy that might allow KML files to be accessed via mobile phones over 3G?


How to make 3D building models from lidar data?

I have Lidar data, ground points and first returns. I have processed it and have ready tiles from which I am trying to build 3D building models. So far I was able to just extrude the buildings in the ArcScene and that is it. I am a beginner in GIS/Remote Sensing and any help would be highly appreciated. Also, I am trying to work this out in Arc10.


How to register table with geodatabase with a command line?

Is there a way to register with geodatabase a table stored in an Oracle 11g database, without using ArcMap or Python script? I'd like to do it with a command line like when registering with ArcSDE (sdelayer -o register ...)


How can I create 1 seamless tab file for master map?

This is my first post on here so please excuse if it's in the wrong place. I've processed some mastermap files which display absolutely fine. However, during the processing it would not let me create just 1 seamless tab file as the index was over 2Gb. I therefore had to split it in to attributes, i.e. Topo_Point_Seamless, Carto_Area_Seamless etc. Now although these work if you load them all separately, it makes it more awkward to work with. Ideally I'd like just 1 seamless tab file i can turn on and off in MapInfo and geoset's etc. However i've tried the seamless creator in MapInfo (11.5) but it says I cannot create a seamless file from other Seamless files. Does anyone know how i could go about this? Many thanks, Nick


arcgis server performance comparison

Are there any recent comparisons/studies of arcgis server vs. open source gis servers in common tasks like providing a wms/wfs, filtering data/search performance, and so on? We received a lot of critic about featuring this thesis on our blog as the thesis is outdated and a little bit picky on serving WFS only. Citation from reddit: "This is like comparing two cars based on cup holder design." There is an older presentation given here but like written: It's from 2010


How to use wildcard when appending PDFs using ArcPy?

I'm working on a script that (as written) produces a large number of individual pdf pages (>100), instead of hardcoding the names of each of the outputs, I was thinking of using a wildcard. However, neither of the following seem to work:                pdfDoc.appendPages("C:\\temp\\*.pdf")      or                pdfDoc.appendPages("C:\\temp\\"*".pdf")      Below is the full script:               mxd = arcpy.mapping.MapDocument("C:\\temp\\Graffiti_DM3.mxd")     df = arcpy.mapping.ListDataFrames(mxd, "*")[0]     graffitilyr=arcpy.mapping.ListLayers(mxd, "*", df)[0]          newquery = '"Incident_Z" =' + "'10003'"     graffitilyr.definitionQuery=newquery     features = arcpy.SearchCursor(graffitilyr)     count = 1               for feature in features:             df.rotation = "0"             arcpy.SelectLayerByAttribute_management(graffitilyr, "NEW_SELECTION", "FID=" + str(count))             #df.extent = graffitilyr.getSelectedExtent(True)             df.zoomToSelectedFeatures()             df.scale = df.scale * .001             arcpy.RefreshActiveView()             df.panToExtent(graffitilyr.getSelectedExtent())             #df.scale = "1000"             outpdf="C:\\temp\\" + str(count) + ".pdf"             arcpy.mapping.ExportToPDF(mxd,outpdf)             count = count+1          pdfpath="C:\\temp\\pdfbook.pdf"     pdfDoc = arcpy.mapping.PDFDocumentCreate(pdfpath)     for pdf in pdfs:              pdfDoc.appendPages("C:\\temp\\*.pdf")     pdfDoc.saveAndClose()     del features     del pdfDoc      Any help would be much appreciated


Classic United Kingdom Projection?

When you visit a classroom in the United States and see a map of the contiguous states on the wall, it's usually in NAD83 Albers Equal Area with the central meridian right at 96 West. Is there an equivalent for the UK? Or to phrase it another way, what's the most common projection when viewing a map of the UK?


Is there a way to identify features on OpenStreetMap.org?

Is there an identify features option for OpenStreetMap.org (OSM.org)? Stemming from this question: How to get shapefile of river from OpenStreetMap? I'm looking for the ability to use OSM.org to figure out the tags and values for features I want to download through the Overpass API, or even QGIS for that matter. If there was a way to use OSM.org to browse the data of OSM through the map interface, then click on a feature to get the information about it. Currently, if you know what a feature is called, you can search for it, and you get the information I'm referring to as the output: ![enter image description here](http://i.stack.imgur.com/mBYYe.png) This would be the exact information I would expect if I were to use an Identify button and click on a feature on OSM.org. This would greatly help, as the first referenced post suggests, the ability to pull down specific data from Overpass API or QGIS. Thanks!


Annotation Published to my ArcGIS Server is being displayed as a point when I build my application with ArcGIS Viewer for Silverlight. How do I get the annotation to display as text and not a point feature?


Applying distance/area dependent procedures in geographic coordinates over large areas?

I'm currently doing some niche modelling with data in geographic coordinates spanning all of Latin America. I am using R for my analysis. Some of the tasks I have to perform are area/distance dependent and yield incorrect results when applied in geographic coordinates. For example, spatial sampling (sp::spsample) leads to a bias towards more points in southern South America and buffering points and polygons (rgeos::gBuffer) leads to stretching/skewing of the buffer away from the equator. What's the best way to address this issue? Should I project my data, apply the necessary procedure, then project back? If so, what projection would work for such a large area? Ideally, I'm looking for a general approach that could be applied to any region, but I fear this doesn't exists.


Where can I find block (sub-district) level boundaries for India?

I'm looking for block (sub-district) level shapefiles for India. The GADM database only has files for the 2300 Tehsils, whereas I'm looking for the about 5500 Census blocks (sub-districts) for any year possible. Thanks.


Info Template not getting displayed

I have a layer like,               realTimeLayer = new esri.layers.GraphicsLayer();      I have an infoTemplate like,               infoTemplate=new esri.InfoTemplate("/*Content goes here*/");      I am creating a graphic, adding it to the layer and plotting the point like,                var graphic= new esri.Graphic(candidatePoint,candidateSymbol,attr,infoTemplate);      realTimeLayer.add(graphic);      map.addLayer(realTimeLayer);      points.addPoint(candidatePoint);      In this case the info template works fine. But during some other event, I am adding the graphic like               var graphic= new esri.Graphic(candidatePoint,candidateSymbol,attr,infoTemplate);     map.graphics.add(graphic);     points.addPoint(candidatePoint);      But this time, I don't get the info template in IE9 even after clicking on the push pin. What could be the reason? And how should I correct this?


Mapping Kansas City based on X and Y Coordinates in R

I have a csv file in R that has coordinates of Kansas City, however, the values at these points aren't in any traditional longitude/latitude formatting that I am aware of. My data looks like this:               Tract            X               Y     218.01       2797574          1143595     218.01       2799346          1144802     133.02       2786207           998301     ...      Is there anyway that I can generate a map from this type of data that will also eventually allow for the visualization of other variables such as population or crime rate?


MapServer and OpenLayers: Properly using MAXSCALEDENOM in mapfile (google baselayer)

My base layer: google map My points on the map: from an airports.db file, set up as a WFS layer in the OpenLayers code. As of now: map loads, points in the correct places on the map. My goal: when the page loads in the browser, the points should not display on the initial zoom. When you zoom in to the second level, they should. I've successfully done this before using just an OpenLayers map, but never a google map as a base layer. For `MAXSCALEDENOM` I've tried all sorts of values, but the points are always displaying. Here is the Airports `LAYER` in the mapfile.               LAYER                 NAME Airports                 DEBUG 5                 METADATA                         "wfs_srs" "EPSG:3857"                         "wfs_title" "Airports"                         "gml_featureid" "Name"                         "gml_include_items" "all"                         "wfs_enable_request" "*"                         "wfs_encoding" "UTF-8"                         "wfs_extent" "-180 -90 180 90"                 END                 TYPE point                 STATUS ON                 MAXSCALEDENOM 20000                 LABELITEM 'Name'                 CONNECTIONTYPE OGR                 CONNECTION '/tmp/navhome/navdata/airports.db'                 DATA 'select "POINT(" || LONG || " " || LAT || ")" as WKT_GEOMETRY, * FROM airports WHERE name LIKE "S%"'                 #DATA 'select "POINT(" || LONG || " " || LAT || ")" as WKT_GEOMETRY, * FROM airports WHERE ICAO != "ZZZZ"'                 PROJECTION                         "proj=latlong"                         "ellps=WGS84"                         "datum=WGS84"                 END # PROJECTION         END # LAYER      Here is the OpenLayers code for the WFS layer:               var wfs = new OpenLayers.Layer.Vector("Airports", {                 styleMap: new OpenLayers.StyleMap({                         externalGraphic: "red_pin.png",                                 graphicWidth: 18,                                 graphicHeight: 18                 }),                 wrapDateLine: true,                 strategies: [new OpenLayers.Strategy.Fixed()],                 protocol: new OpenLayers.Protocol.WFS({                         srsName: "EPSG:3857",                         version: "1.0.0",                         url: "http://my_url/cgi-bin/mapserv.exe?map=/tmp/navhome/navcore/airports2/airports_viewer.map&SERVICE=WFS&VERSION=1.1.0&srsName=EPSG:3857",                         featureType: "Airports"                 })         });         map.addLayer(wfs);      Any input on this matter is appreciated. I assume it has something to do with the extent, but I'm not totally sure.


Geoserver WFS Point Coordinates

I'm using SharpMap's desktop client within a C# WinForms application and GeoServer/PostGis as datasource. When i add a WFS layer that contains Multi-Line it works like charm. But if i add a point layer, SharpMap.Utilities.Wfs.ParseCoordinates function parses coordinates with the wrong order. I meant that sharpmap assigns X coordinate to Y and Y to X. ParseCoordinate function is like that:               protected Coordinate[] ParseCoordinates(XmlReader reader)     {         if (!reader.Read()) return null;              string name = reader.LocalName;         string coordinateString = reader.ReadElementString();         var vertices = new List<Coordinate>();         string[] coordinateValues;         int i = 0, length = 0;              if (name.Equals("coordinates"))             coordinateValues = coordinateString.Split(_Cs[0], _Ts[0]);         else             coordinateValues = coordinateString.Split(' ');              length = coordinateValues.Length;              while (i < length - 1)         {             double c1 = Convert.ToDouble(coordinateValues[i++], _FormatInfo);             double c2 = Convert.ToDouble(coordinateValues[i++], _FormatInfo);                  if (name.Equals("coordinates") || name.Equals("pos"))                 vertices.Add(new Coordinate(c1, c2));             else                 vertices.Add(new Coordinate(c2, c1));         }              return vertices.ToArray();     }      I've changed order of c1 and c2 values to fix that problem but not sure why it's acting like that. Here goes the GML output of my geoserver:               <gml:coordinates xmlns:gml="http://www.opengis.net/gml" decimal="." cs="," ts=" ">     51.52672002,25.33049886     </gml:coordinates>      X = 51 and Y = 25 but reader.ReadElementString(); statement at ParseCoordinates function reads them like that: 25 and 51 I'm not sure if it's due to geoserver's configuration or sharpmap's bug.


CartoDB preferred file type

I was wondering if anyone knew the preferred upload file type is for CartoDB.I upload zipped .shp files for polygons, and sometimes .csv file for point data. I noticed that when I uploaded a zipped .shp file it hit the 50mb account limit even though the file only ended up being 9mb in cartodb when I upgraded accounts. Is this becasue it is duplicating the table during processing? Is there a preferred file type for cartoDB? GeoJSON? thanks,


Questions regarding the processing of mosaic Landsat 8

**Approximate Translation of Original Question:** A question of theoretical and practical about the mosaic of satellite images. I have 3 different months of Landsat images, which need to accomplish the end MaxVer classification. At what point should I make the mosaic of 3 scenes? before or after sorting? Follow the steps ... Acquisition >> Georeferencing >> Atmospheric Correction >> Classification >> Mosaic or Acquisition >> Georeferencing >> Atmospheric Correction >> Mosaic >> Classification **Original Question:** Uma dúvida de ordem teórica e prática a respeito do mosaico de imagens orbitais. Possuo 3 imagens Landsat de meses distintos, a qual necessito realizar ao final uma classificação MaxVer. Em que momento devo realizar o mosaico das 3 cenas? antes ou depois da classificação? Segue as etapas... Aquisição>>Georeferenciamento>>Correção atmosférica>>Classificação MaxVer>>Mosaico ou Aquisição>>Georeferenciamento>>Correção atmosférica>>Mosaico>>Classificação MaxVer


Interpretation of ArcGIS Kernel Density legend parameters

In ArcMap 9.3 I've used Kernel Density to map various incidents, but the resulting shapefile doesn't display any units of measurement. Is there a good, not-to-technical source that would explain in lay terminology the interpretation of the output values in terms of the input cell size and search radius?


Get number of rules in geoserver style using webservice

how can I know the default style for a layer in geoserver, and the number of rules it contains, using a REST call or service? Thank you bye stefano


How to pre-populate JavaScript forms in ArcGIS Web Application?

I have an ArcGIS web application and would like to pre-populate order numbers. Say if order 1 has been entered for a point on a map, when the next point is added, order 2 would populate automatically. Of course these numbers are a series of letters and numbers, say abcd1234, next order would automatically populate abcd12345. I am using SQL server to submit new features with feature access capabilities. The web application is using the JavaScript API. I have the code hosted on an IIS web server in order to access the actual JavaScript.


OpenLayers Clustering Adds Features to Selected Features Array on Zoom

This is my first posted question despite using StackExchange for a few years now. I've been stuck for quite some time trying to figure out this issue with OpenLayers. The problem is as follows: I have a bunch of features plotted on a map and am able to select features in various ways (e.g. drawing a box around them, clicking on individual features, entering a zip code that selects all features within that zip code, etc.). This all works fine. The issue is that I have a clustering strategy on the features layer and when I zoom out, currently selected features get clustered together with unselected features and those unselected features will become selected when I zoom back in. What I'm trying to accomplish is to NOT have the previously unselected features become selected after clustering. Here is a link to a visual hosted on my website (http://korynorthrop.com/uploads/Visual.jpg) I could post some code as well, but thought I'd simplify this question first.


Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values on the bar, similar to the old plugin "One-Band Raster", that it doesn't work with the Qgis version higher than 1.7 I tried to set in properties->style, where I selected the Render Type "Singleband pseudocolor" and see the "generate new color ramp" box. I tried both "Continuous" or "Equal interval". However, in the Composer the legend always is displayed with discrete symbols. Is there any way that can make QGIS Composer to display a nice continuous band for a raster layer?


Help, I have 10,000+ .shp files covering 3 UTM zones with unknown projections

I was handed a ton of property files with no projections attached but was told they are all in UTM zone 21S. Well once I merged them all together and projected them I realized that the data covers 3 UTM zones 20S, 21S, and 22S. So basically each property file could be one of 3 UTM zones. Is there a way to figure out what UTM zone each property file belongs too without checking each one at a time? I can python code if need be. I'm using ArcMap 10.2 I tried that. Here is a more detailed explanation of my situation. These files were original downloaded by UTM zone. So all properties in UTM z 20S were downloaded together with a projection of UTM z 20S, all properties in UTM z 21S were downloaded together with a projection of UTM z 21S ect. The shape files I received didn't come with the .prj files and I have no way to obtain them. So when I project them all with the same coordinate system say UTM z 21S, they overlap, all of the property files from UTM z 20S and 22S are overlapping the correctly referenced properties of z 21S. The misplaced properties are located in the correct area of the UTM zone, just the wrong one. Does that mak sense?


How do I get GeoJSON data from GeoServer into show up on my Leaflet map?

I'm trying to create a simple "Green" map for my city. The idea being that it is a website with a map and layers you can turn on and off. I am serving the data through GeoServer and am using GeoJOSN to add the data to the map. I checked the URL for the data and GeoServer is serving up the file in GeoJOSN format. Eventually I would like to be able to let the user to click on the points on each layer to get more information but I need to get the data showing up on the map first. The leaflet code below is pretty simple but I can't seem to get the data to show up on the map. I refereed to the Leaflet documentation but can't figure it out. I'm guessing I am just leaving something simple out due to my lack of knowledge about Leaflet. Leaflet web mapping ninja's, a little help please.


How <-> operator work?

I'm doing a search to find links close to a point.   The problem is if i limit to 20 result i found the closer link at 6mts   but if i limit to 10 result that link doesnt appear and the closest link is at 17mts Shouldn't the top 10 closest link to my point appear in both querys? I'm using PostgreSQL 9.3.2, POSTGIS=2.1.1 ![query result image](http://i62.tinypic.com/2a65agm.jpg)                   SELECT              S.Seg_ID,              S.Link_ID,              S.Course,              ST_Distance(ST_GeomFromText('POINT(-66.879670 10.497950)',2309), S.geom  ) as distance         FROM vzla_seg S         ORDER BY S.geom <-> ST_GeomFromText('POINT(-66.879670 10.497950)',2309)         LIMIT 20


Extract raster values under under each polygon buffer in qgis

In qGIS: I have raster file and >100 points. I constructed buffers polygons (vector-->geoprocessing-->buffer) around each of the points. Than I clipped (raster-->extraction-->clipper) the raster file with the buffer polygons, resulting in a further raster layer. How do I get the raster values under each of the polygon buffers? My tiff as pixels, which can have five different values (222, 333, ...) and I want to know how often each value appear under each polygon (e.g. polygon I: 10 x values 222, 100 x value 333...; polygon II: 35 x values 222, 50 x value 333...; )


Finding the Default version in a large linage tree

I have a very large versioning linage tree. I am using the arcGIS 10.0 GDBT tool. How can I find the node with the default version? ![enter image description here](http://i.stack.imgur.com/Ptz2a.png)


ArcGIS online live data

Does ArcGIS online have the capability of providing real time (live) tracking of assets? If I have a staff member with a cell phone can ArcGIS online show me where that person is at any given moment? I have ArcGIS desktop. I do not have ArcGIS Server.


Merge lines with the same 'name' attribute on QGIS?

I have a shapefile with a few thousand lines, each is a street segment. I'd like to merge all features with the same 'streetName' attribute into a single attribute. I only really care about the name of the street and it's geometry. What would be the query necessary to do such a thing? I'm new to GIS in general and have run into a problem I can't figure out how to fix. Excuse my noobness. Thanks in advance.


Taking attributes from state road data and adding to over lapping route data

Ok so... I am working on a project that is looking at the regional public transportation within my area and comparing it to the overlapping road systems. I want to display the different attributes that these routes run on to give recommendations as to what kind of development should go in certain areas. So the attributes that would be in play would be speed, sidewalk access, bike lane access, as well as a couple of other things. I have created the shapefile of the routes and I am going to compare them to the ISRN shapefile that I got from DOT. How would I go about taking these ISRN attributes and moving them over the shapefiles that I have created as well as the bike paths and sidewalks.


ArcPy Create Point Along Line A Specified Distance From A Specified Point

In ArcGIS Basic I am trying to take a road polyline(one segment for the entire length of road) and get a point placed on the map a specified distance from an intersection. I have a layer of intersection points and the layer of roads. I need to tell it to place a point on the polyline where the starting intersection point is. Then travel the specified distance down the line and place a point for a sign. Any suggestions? I am currently trying to write a script to select a road and points and create a temporary layer of each. Then from that temporary road I CreateRoutes_lr. Then take the intersection point and LocateFeaturesAlongRoutes_lr. From locating the point I would like to take the "fmp" from distance as a variable. Is there any way to extract it?


Layer tick boxes embedded in PDF map

Maybe this is more of a PDF question than a GIS question. Today, I received a layered PDF map shown as a landscape A3, with a square map on the left, and with the map title, the legend, the scale, a tiny overview map etc. on the right-hand side. However, each legend item had two tick boxes beside it: one for switching on/off the symbols and one for switching on/off the labels. It also contained radio buttons to switch between various background maps. I thought this was really elegant, and would like to create something similar. I know how to create a layered PDF in ArcGIS, and then go to the Layers toolbar in Adobe Reader to switch on/off layers in the map. However, I'd like to know how I can embed the layer control inside the map. (Note: I am not looking on how to draw individual tick and radio boxes, as I feel it's done by some application (semi-)automatically) EDIT: Here is a picture of it, cut down to the bare minimum for copyright reasons ![Tick boxes and radio button in PDF map](http://i.stack.imgur.com/Ie2BS.jpg)


Create a raster from file geodatabase featureclass based on a field from a related table

I have a USDA Statsgo soil polygon featureclass stored in a file geodatabase along with an attribute table; I have a one-to-one relationship class defined based on the soil type field. When I bring the featureclass into ArcMap I can view the attributes in the related table when I use the identity tool. What I would like to do is create a raster from this featureclass using values from the related table. This seems simple enough, but when I used the Polygon to Raster conversion tool the only fields available to use are those which are stored in the featureclass itself. If I define a join on the same featureclass and table I can then select the appropriate field in the joined table, which makes me wonder why I bothered creating the relationship class in the first place (resulting raster values are numeric - I lose my classification codes of A through D). Can anyone explain 1) why I can't use the relationship class to access fields in the related table, and 2) how to keep the alphabetic soil classification codes?


Fastest way to transform WKT in python

Is it possible to use pyproj to transform WKT without creating geometry objects such shapely geometry, GEOS geometry or OGR geometry. If not what is the fastest way to do it?


esri ArcGIS javascript api compatibility with Internet Explorer 7 and 8

I've developed a web map using esri arcgis javascript api version 3.8 and its not compatible with IE 7 or 8. I've advised the people who have reported this to update their version of IE but, if it doesn't involve rewriting the website, I'd like to offer something that can work with these versions. Here's the website: http://il.water.usgs.gov/data/mchenry/map.php As you can see, in IE 7 or 8 the map doesn't even load which throws javascript errors. _EDIT_ I have added some script that changes the markup and css to handle HTML in IE versions lower than 9 found here: http://stackoverflow.com/questions/5449502/html5-and-css3-for-ie7-and-ie8 Since doing this, I've noticed that the map loads on zoom in/out but none of my points load.


Fixed Zoom Extend For Overview Map on ArcGIS Server JavaScript API 3.8

Can some one please let me know if it is possible to have the Map Overview with Fixed extend and none zoom in or out functions? I know this was not possible on v.3 but how about v3.8? Thanks


Edit web.xml in Tomcat 8

Need to edit the web.xml tomcat 8 to increase the size allowed for me to do deploy war file geoserver. I was in C: \ Program Files \ Apache Software Foundation \ Tomcat 8.0 \ webapps \ manager \ WEB-INF and open the notepad in the sublime but I can not edit it says is being used by some program. Have stopped tomcat and I closed the program and web administration page. Where this file may be in use?


Change from polygon to multipolygon in postgres

can somebody describe please how to do the transformation from polygon to multipolygon in the postgres DB, is not possible for me to save my edited data. All data loaded just need to do some editing upon my polygons Thanks in advance regards


Using 'construct points' on all lines in a shapefile (arcpy)

I need to use the editing tool 'Construct Points' on several shapefiles that each have ~1300 polylines. I need to do this to create points every 1km along each of the polylines, which represent the orbits of a satellite. I've tried several other methods such as densify but none of them solve my problem as well as 'Construct Points'. The only problem is that you can only edit one line at a time, which would obviously take too long to do manually. So I'm wondering, is there a way to implement 'Construct Points' in python so that it loops through all polylines and applies the tool with the same parameters? I feel like it should be possible, but I've never used editing tools in arcpy so I'm not sure. The output of 'construct points' is a point shapefile for the points that were constructed along the line used as an input. I'm wondering if I could do it in python such that it constructs the points on the line, then appends the output points to a larger point shapefile. The following is pseudo code of what I have in mind, although the syntax is of course not correct. If anyone could shed any light, that would be great. I really would like to know if this is even possible with arcpy before I spend time trying to pursue it. Thanks!               # using just one shapefile as an example (pseudo code, incorrect syntax):          orbitshapefile = (shapefile with ~1300 polylines)     pointshapefile = (empty shapefile to store points)          StartEdit(orbitshapefile) # open editing on the shapefile     for orbitline in orbitshapefile:         editor.ConstructPoints(orbitline, 1km, ..(other parameters).., outputpoints) # call editing function         pointshapefile.append(outputpoints) # append output points to 'big' shapefile      EDIT: I just did construct points manually on just 2 lines in editor and found that using the same point shapefile on the second line that was used with the first adds those points to that shapefile, doesn't overwrite them. However, I need an indication of which line these points came from. There is an 'Id' attribute in the resulting table, but everything is 0. Would there be a way to carry over the line's FID to all the points that came from it (alt. I could do a separate script after that uses intersect b/w line and points to come up with a lineID attribute). An updated version of the above code:               for orbitline in orbitshapefile:         lineID = orbitline.FID         editor.ConstructPoints(orbitline, 1km, ..(other parameters).., outputpoints)         outputpoints[pts that were just created in this iteration].SetAttribute(lineIDField = lineID)               Some additional thoughts: I'm not sure how to subset the points that were just created-- maybe I could subset by saying something like: points in outputpoints s.t. lineID == 0 (because all points that were created in previous iterations will have their lineID attribute set to something other than 0) Any thoughts on this rationale? Thanks so much PS: Can anyone AT LEAST tell me if using an editor tool iteratively in python is even possible?


GeoDjango Changing My Coordinates

I'm running into a problem when saving a coordinate into one of my models in (Geo)Django. My point field is setup as:               location = PointField(blank=True, null = True)      So while running some tests in the django shell I noticed my coordinates were changing...               obj.location = 'POINT(-120.18444970926208 50.65664762026928)'     obj.save()     print(obj.location.x)      **-120.1840742**               print(obj.location.y)      **50.6569673** Another thing I've noticed If I set the point using an UPDATE in postgres and then...               print(obj.location.y)      **50.65664762026928** but if I run a save and check the coordinate again I get...               obj.save()     print(obj.location.y)      **50.6569673** Anybody have any ideas where I can start looking to sort this out or any suggestions what may be causing this. Thanks, Dustin Software:   * Django 1.3.1    * GDAL 1.9.1    * Python 2.7.2    * PostGIS 1.5.3    * GEOS 3.3.3   * PostgreSQL 9.1.4


Openlayers WMS layer always sends "EPSG:900913" as srs parameter

Why the wms layer ignoring srs parameter srs:"EPSG:4326" and always sending "EPSG:900913" as srs value..? this the code,                   map.projection= new OpenLayers.Projection("EPSG:4326");              var wmslayer = new OpenLayers.Layer.WMS("Cities",      "http://{208.184.113.91}/ArcGIS/services/BurkeMcDowell2013_06_26FORGOPI/MapServer/WMSServer?service=WMS",                                                          {layers: '0',             srs:"EPSG:4326",             transparent: true            },{            projection: new OpenLayers.Projection('4326')           });


How to display a table with more than one geometry column in QGIS?

In PostGIS, it is possible to use addgeometrycolumn more than once on the same table. Example: I have one table "scenes" with many attributes, and 2 geometry columns: the_geom1 and the_geom2.               select addgeometrycolumn('scenes', 'the_geom1', 0, 'POLYGON', 2);     select addgeometrycolumn('scenes', 'the_geom2', 0, 'POLYGON', 2);      In QGIS, when I display "scenes", it only displays the_geom1. To display the features using the second geometry, I found a solution with :               create view v2 as select id,the_geom2 from scenes;      But I'd like to access all other fields; something like:               create view v2 as select * (except the_geom1),the_geom2 from scenes;      Any ideas ? Thanks, Eric.


Creating a Raster Filter

I am looking to create a raster filter which reclassifies single or contiguous pixels less than, for example, 30 pixels (shown in white below) into another class (shown in black). The filter, majority filter, aggregate and other spatial analyst generalization tools seem to be too over reaching in this case. Any Python or Arc solutions and ideas would be appreciated. ![enter image description here](http://i.stack.imgur.com/JmyJ4.jpg)


Extract portion of WMS raster layer

Using QGIS on Windows XP based desktop. I am trying to use USDA orthophoto data from this WMS server: "http://raster.nationalmap.gov/arcgis/services/Orthoimagery/USGS_EDC_Ortho_NAIP/ImageServer/WMSServer" I can get the layer into QGIS with no problem but the only layer on the WMS server is of the entire United States. I want to extract from that the area I am interested in (a city). I have a vector layer of that city to use as a clip coverage but GDAL can only clip from a local raster layer. I have probably left out some pertinent information so please just ask if you need more information.


Aligning coordinate systems: gpx, LiDAR, shapefile

I am working on a project based on a lidar data set (for use in LidarViewer in Linux, a basic x,y,z viewer) that was downloaded from #1 below at Opentopo.org and looking to add onto this data set with a shapefile based layer and a gpx based layer. In ArcMap 10.0 I am converting the shapefile (road perimeter around lake) into points, then Defining the Projection in Arc Toolbox's Projections and Transformation. Since Opentopo stated UTM Zone 10, I set that to the roads shapefile, exported, completed my .shp to .las(lidar file) conversion and sent it to LidarViewer. In LidarViewer my LiDAR data (only a section of the lake's perimeter) is floating the in the middle of the lake (with perspecitve to the road points). So, I switched the Tahoe to the original NAD27 in ArcMap, went through the process again with no change in position. Do I have to have a shapefile based on NAD83 for this to work, or is there another way? Lidar viewer imports .las or .txt/.csv files and only reads a x,y,z no coordinate system whatsoever. The other related question is with the .gpx data that I am downloading from the #3 below, it is a .gpx file of a bike path around the perimeter of the lake. I am using the following link to convert .gpx into a text file (to process and import into Lidar Viewer) and the site provides the ability to output long/lat plus UTM coordinates (the output included both zone 10 and 11 South ) This .gpx file also does not project correctly. I was thinking that I should possible try another converter? gpsvisualizer .com convert_format=gpx Any input regarding the above two questions are appreciated, I can also further clarify any issues that may not seem clear. Thanks! 1) opentopography-org -> Data -> South Lake Tahoe, Nevada Horizontal Coordinates: UTM Zone 10 N NAD83 Meters [EPSG: 26910] - Vertical Coordinates: NAVD88 2) tahoe usgs gov/DLG UTM NAD27 zone 10 projection 3) bicycling. trimbleoutdoors. com/ViewTrip.aspx?tripID=153934


Options for a historic Web Map?

EDIT: I'm an intern at a small local history museum. We have a budget of $0. Project overview:   1. I've got a bunch of old paper maps. When I say old, I mean 1800s and up. They've been scanned into TIFFs. I geo-referenced them and exported as GEOTIFFs. I've digitized the components of the maps we are focusing on (railroads, roads, etc).   2. The goal is to construct a web application (I've used ESRI's ArcGIS Online for a different web map project with CSV data) that allows a user to select layers (of years past) to view how transportation has developed in our county. Aside from a layer selector, layer opacity needs an option to be changed.    3. I've looked into MapBox API, but it lacks opacity sliders. QGIS Web Client looks promising and similar to the ArcGIS Server Client, but I wonder if it is too complicated for our end-users. I don't have much time to get this together, nor do I have much in the way of heavy programming experience.


How to save a newly created shapefile in PostGIS?

I am creating shapefile using shapefile.py and my database has records more that 65k which is the limit of the shapefile. How can I create shapefiles then? Is it possible that somehow I am able to creat shapefile and store them directly into the PostGIS using shapefile.py?


ArcGIS Server GP Service - RasterIO.dll crashing ArcSOC.exe

I've been having a terrible time this week turning some very simple geoprocessing scripts into gp services on ArcGIS Server 10 SP 4. In the case of the linked post, I found that using certain raster formats seemed to be the trouble maker on ArcGIS Server. Once again, I have a small, simple script that performs a viewshed analysis. It runs perfectly from ArcGIS desktop. As a gp service, all hell breaks loose... Whats interesting about this case is that the analysis itself completes without error. All of the processing is done within a gdb - and all output feature classes are being produced. This eliminates the possibility of a permission related error. The output of the gp service is a feature set - to be loaded from one specific feature class in my processing file gdb. The feature class is always there, however the gp service crashes before the feature set is ever sent to client. When I log into the ArcGIS Server, there will be windows message box open saying the ArcSOC.exe has stopped working. Looking the Event Viewer; the faulting module is RasterIO.dll. ArcGIS Server has no log entry for this crash. All attempts to trap any errors in the python script itself dont yield anything either. Has anyone experienced anything similar, or have any idea how I can get more useful information on the exception.


Insert last coordinates from a list of coordinates with line ID into a multipart polyline feature class

I'm having problems creating the last line from a list of coordinates that I have. I have a text file with coordinate data with a X, Y, and a Line ID (LID). I read the file and inserted each attribute into a coordsList[]. CoordsList has 234 coordinates with an [LID, X, Y] here is my code looping through the list and inserting each set of coordinates for one line into the feature class.               lineCursor = arcpy.da.InsertCursor(lineFC, ["SHAPE@"])               id = -1 #id to identify if which points go to which lines     for coords in coordsList:         if id == -1:             id = coords[0]              if id != coords[0]:             lineCursor.insertRow([arcpy.Polyline(lineArray)])             lineArray.removeAll()         lineArray.add(arcpy.Point(coords[1], coords[2], ID=coords[0]))         id = coords[0]          lineCursor.insertRow([arcpy.Polyline(lineArray)])          del lineCursor      What am I missing? The feature class is populated correctly until the last line. Then only one of the coordinates is capture so lineArray doesn't contain two coordinates to create the line. There is a record with no geometry? Any direction would be much appreciated.


Convert census data to points

I have data from the Census Bureau's LEHD files that record number of jobs within blocks using the digit 1 to denote one job. I want to convert the number of 1's in the column into a feature that I can use to calculate block density of the number of 1's in the block. How do I do that? I have read something about using the Float to Raster tool but I am not sure how to use it. The table with column reading "S000" is total employment by block. However, that "1" you see is really a point not a number. So I want to create a buffer of a one mile radius and count the density of 1 per sq mile. ![original data](http://i.stack.imgur.com/F6bmC.png) ![joined data](http://i.stack.imgur.com/jEMW2.jpg)


How can i convert from local coordinates to coordinates gps?

i don know if this is the right place to publish this. i am working with business object tool traying to make a kml file to be imported on google maps. I dont know much about geographic systems, but i begin to understand some basic thinks, well, i have a database which give me a local coordinates i know that becouse the gps has an appfile which has a grid configured and the database says me that units are meters. ## The app file shows this information Site Point Pairs:   Number Of Points: None Ellipsoid:   Name: (WGS 84) Semi Major Axis: 6,378,137.000 Semi Minor Axis: 6,356,752.314 Flattening: 1/298.2572215381 Eccentricity:   First: 0.0818191911 Second: 0.0820944382 Datum Transformation:   Name: (WGS 84) Method: Molodensky Parameters: Direction: WGS84 to Local Translation X: 0.000 Translation Y: 0.000 Translation Z: 0.000 Geoid Model:   Name: Subgrid of MEXICO97 (Mexico)   Method: Grid Geoid Grid File Name: Coordinate System:   Name: 12 North Group: UTM Projection: Type: Mercator Transversa Parameters: Latitud central: 0°00'00.00000"North Longitud central: 111°00'00.00000"West Falso norte: 0.000 Falso este: 500,000.000 Factor de escala: 0.9996 AZI Parameters: Azimuth Direction: North Azimuth Positive Coordinate Direction: NorthEast Embedded Data: True Embedded Geoid Grid Extents Minimum Latitude: 30°53'60.0000"North Maximum Latitude: 31°18'0.0000"North Minimum Longitude: 247°03'60.0000"East Maximum Longitude: 247°33'60.0000"East CSIB Version: 10.50 CSIB Format: Big Endian * * * the database shows me this kind of values vehicle x y z VE-28 328279 3457947 -48   VE-28 328295 3459609 192   VE-28 328288 3459617 193   VE-28 328304 3459622 192   VE-28 328220 3457362 -112 i would like to conver this unit into gps information throught some formula. or get the gps give the gps coordinate to the database instead of the local coordinate. if something is confusing please ask me for more information.


How to display GIS Diploma on a buisness card?

I was wondering if there was a standard way to display a GIS diploma for email signatures/business cards. Thanks


How can i use ihookhelper interface in python?

I use ArcObject in python to develope a tool. I import comtypes in python to access the arcmap layers in python and use ifeaturelayer interface. I have to set featurelayer to phookhelper.focusmap.get_layer(i) to access the layers in ArcMap. The problem is that I can't find get_layer method in python. Is there any way to access the ArcMap layers in python using ArcObjects?               for (int i = 0; i < phookhelper.FocusMap.LayerCount; i++)                 {                     if (phookhelper.FocusMap.get_Layer(i).Name == comboBox1.Text)                     {                         pfeaturelayer = (IFeatureLayer)phookhelper.FocusMap.get_Layer(i);                              pfc = pfeaturelayer.FeatureClass;


Trilateration in 3D with signal strengths

I'm having a hard time getting my head around the maths to locate a target in 3D given a number of known points (4 or more) and a value that indicates the signal strength (range 0–100). I've looked at the simpler answer in the 2D case but I'm unsure how to generalise the idea of normalising the signal strengths for the 3D case. It might even be that this answer is too simple for my requirements. I know that in my case the signal strength is proportional to distance-2 but do not know the propagation constant. I've also seen this question, but it's not quite what I'm after as I want to use the signal strengths from a larger number of nodes to improve the estimate.


GDAL does ECW but QGIS (Linux !!) does not load ECW file

Followed instructions from various posts (each one with slight variations on the theme) and most of the time have no trouble getting the installed GDAL to accept ECW files. However, QGIS stubbornly refuses to accept the fact that GDAL is ECW-enabled and keeps telling me the format is not supported. As no one even mentions the mere fact that QGIS will NOT work even if GDAL itself does, I must be missing something really obvious somewhere (like the need to compile QGIS from source? How to otherwise get ECW in the list of supported raster files in the qgis settings menu...). Grateful if anyone could point that out to me in simple steps, as I've been spending more then a week now on this. System info: - Virtual machines using VMWare workstation 7 on Win7 Pro. - LinuxMint12 (Ubuntu 11 Oneiric) with QGIS 1.7.4 upgraded to QGIS 1.8.0 and GDAL 1.9 - Clean LinuxMint 13 (Ubuntu 12 Precise) with QGIS 1.8 and GDAL 1.9 as installed from qgis package In all cases gdalinfo --formats list ECW as supported and commandline gdal_translate and gdalwarp work fine with ECW as input and output (translate only), but QGIS knows better and refuses to even try. Tia, Lewie


Deactivating Openlayers Cluster after a certain zoom level

I want to deactivate the cluster strategy after zoom level 16. The Cluster strategy gets deactivated and I also change the style of the original features and redraw the layer. But still it takes the styles defined for the clusters instead of taking the newly defined styles.               var test_style = new OpenLayers.Style({         'fillColor': '#CC66CC',         'fillOpacity': .8     });     var test_style_map = new OpenLayers.StyleMap({         'default':test_style     });                       var test_layer_name=clusterStrategy.layer;     if(zoom_level>16) {         clusterStrategy.deactivate();         test_layer_name.styleMap=test_style_map;         test_layer_name.redraw();     }


How can I transfer data from one PostGIS database to another?

I have quite a bit of GIS data in a old PostGIS Database (version "1.1.6") and I need to transfer it to another PostGIS Database ("POSTGIS="1.5.3"). I tried creating a backup and restoring that on the new Database, but it throws several hundred errors. What is the correct way of transferring the data?


Slow IE8 responsiveness with OpenLayers and many features

# Background Adding about 700 sites to an OpenLayers Map. Firefox 11 and Google Chrome display the sites just fine. IE8, which is the organization's standard and will not be upgraded for the foreseeable future, bogs down when all 700 sites are displayed. Each site has a representative icon, from a set of 15 icons. Clicking on each site displays an informative popup. The popup window is loaded on a per-click basis. The HTML for the popup window is loaded into memory once (and only once) from a single template. Clicking the site reveals the popup, which dynamically loads JSON data and fills in the template on-the-fly (to reduce the memory footprint). This application uses OpenLayers v2.12 (723 kb). # Code The sites are being added to the "sites" layer as follows:               /**      * Adds a site to the list of sites.       */     function addSite( sites, uuid, label, lon, lat, icon ) {       sites.push(         new OpenLayers.Feature.Vector(           getPoint( lon, lat ),           {             uuid: uuid,             siteType: icon,             title: label           }         )       );     }          /**      * Fetches the list of all sites from the query service and adds them      * to the site layer.      *       * @param siteLayer - The site is added to this layer.       */     function addSites( siteLayer ) {       $.ajax({         url: MAP_SERVER_SERVICE + 'sites',         type: 'GET',         dataType: "json",         contentType: "application/json; charset=utf-8",         success: function( data ) {           var sites = [];                $.each( data, function( key, val ) {             addSite(               sites,               val.uuid,               val.label,               val.longitude,               val.latitude,               val.site_classification );           });                siteLayer.addFeatures( sites );         }       });     }      About 100k of JSON data is returned from the map server service (i.e., the Ajax call). # Question How would you load ~700 features into IE8 through OpenLayers without bogging it down? The sites cannot be rendered on map tiles because the icon is dynamic (i.e., different search results will produce different tiles at the same location). # Ideas Some ideas I have considered include:   * _Upgrade_ – Probably not feasible to ask everyone who will be using the application to upgrade to IE9.   * _Browser_ – Might not be feasible to ask people to download Chrome (or Firefox) just to view a web application.   * _Empty Map_ – This would make the map quite responsive initially, but would still bog down when showing a large number of sites. This is the most trivial of solutions.   * _Optimize_ – There is no guarantee that even after optimizing OpenLayers that the site will be more responsive.   * _Restrict Area_ – Define a region of “visibility” (like a rectangular section) and only display sites that fall within that region. This significantly reduces the usefulness of the tool.   * _Site Limits_ – Constrain the number of sites returned for any given search. This would produce misleading results.   * _Hide Overlapping Features_ - Hide sites that are partially hidden by other sites. This is probably produces optimal results. This is a type of cluster strategy. What other possibilities are there to speed up IE8? For what it's worth, the `postDraw` and `createNode` (30.25 seconds) methods of OpenLayers take up most of the application time, according to the IE8 debugger. ## Update #1 To illustrate the amount of data: ![](http://i.imgur.com/VeK8D.png) There are sites that fall outside of the province, but they are literally few and far between. Zoomed in view: ![](http://i.imgur.com/GKbJ3.png) ## Update #2 I thought I could "hide" some of the features, but this does not help:               function hideFeatures( layer ) {       var features = layer.features;            for( var i = 0; i < features.length; i++ ) {         features[i].style = { visibility: 'hidden' };       }            layer.redraw();     }      It looks like they'll actually have to be removed from the layer to be performant. # Related Links   * http://stackoverflow.com/questions/6528243/how-to-hide-vector-features-in-openlayers   * http://stackoverflow.com/questions/6578846/get-distance-in-pixels-between-2-lonlat-objects-in-openlayers   * http://openflights.org/blog/2009/10/21/customized-openlayers-cluster-strategies/ Thank you!


Why my 'add basemap' data seems taking too long to upload the maps in ArcGIS?

Can i know the easiest way or any other way to upload Big maps hybrid from add basemap in ARcGIS 10? because it seems taking quite a long time to upload the map like around more than 1 hour and still nothing happen. The internet connections is excellent and the desktop use are high speed. Is it because it still no comportable with something? can i know the best other way to add basemap from arcgis into layer than add data from GE to match the coordinate with other layer?? Thank you


How do you format an OGR VRT file to best convert a CSV to KML?

I am attempting to get a nice KML for simple review of POI/geocoding from a CSV. I a using ogr2ogr and a vrt. You can see the vet file below, with two attempts to get this right. Basically, the issue is using `ogr2ogr -f KML ...` with the vrt w/o renaming results in a lot of "SimpleData" tags in the KML. I'd like to get some CSV fields as the KML Placemark "Name" and "Description", concatenated fields, actually. `-dsco NameField=RegionName` option in `ogr2ogr`, but I don't see a way to concatenate fields into name, e.g Street, City, State.. In the .vrt below, the `SrcSQL` field results in no records. It does open, but with layer info. The `Field` tag (when not commented out) does result all records with in the new alias, but the "name" is the only field that comes through, it drops all other fields. Further, is there a way to concatenate fields using ? Of course, perhaps ogr is not capable of concatenation ... Thanks for any help! wr               <OGRVRTDataSource>         <OGRVRTLayer name="roofing-poi2">             <SrcDataSource>roofing-poi2.csv</SrcDataSource>             <GeometryType>wkbPoint</GeometryType>             <LayerSRS>WGS84</LayerSRS>             <GeometryField encoding="PointFromColumns" x="Longitude" y="Latitude"/>     <!--         <Field src="StreetAddress" name="name" /> -->             <SrcSQL>SELECT StreetAddress as name</SrcSQL>         </OGRVRTLayer>     </OGRVRTDataSource>


arcpy.UpdateCursor for multiple fields

I've hit a wall trying to loop through multiple fields with arcpy.UpdateCursor. I have a list of files (2) with multiple fields (10-15'ish) that have its own error check in SQL, and an error value to be written. I am wanting to loop through and update each field with its programmed value.                   import arcpy         FILE = 'X:\\SOME_FILE'         FIELDS = [ "FIELD_X", "...", "FIELD_N"]         SQL = "SOME_FIELD = SOME_VALUE" # or less than, greater, etc         for FIELD in FIELDS:             rows = arcpy.UpdateCursor(FILE, SQL, "", FIELD)             row.FIELD = 'FIELD_ERROR_VALUE'             rows.updateRow(row)         del rows      There's a bit more to it, but the short is that row.FIELD is read as row.'FIELD_NAME', with FIELD_NAME as a string value. I'm rather new to the backside of Python programming and got thrown in just to learn. I've worked through many issues, but this one has got me stumped. If row.FIELD would work, it would be easier than going through each single field with it's NAME, SQL, UPDATE_VALUE, etc manually. It works if I type in row.WHATEVER_FIELD = ..., but calling the variable (from string) adds a ' to both ends as a string value. The only thing not working in the loop is row.FIELD. I'm working with python2.6, arc10.0, mostly win7. Any help would be greatly appreciated. GM


Create drive time polygon around a map point

I'd like to create a 30 min drive time polygon around 400 separate points I have plotted to google maps. I have discovered http://www.freemaptools.com/how-far-can-i-travel.htm but this seems to freak when you get near the sea (many of my points are). And also http://cartoo.dyndns.org/ which works well, but I can't then extract the polygons in .KML form. Anyone come across any tools able to help me? Cheers Chris


How to calculate the area of a polygon considering the relief?

I work in a fire department and i'm mapping all the fires that occur in my area, creating polygons that represent burnt areas. my problem is that the values are not accurate... for instance, arcgis calculates one of the polygons as 51000 square meters when, in reality, I know that the real area is 60000 square meters. the issue is that the relief is not being considered for the measurement and I need to have the most accurate possible values. is there any way to calculate an area considering the relief in arcgis 9.3? tia


Find the minimum elevation pixels from an elevation raster using arcpy

I want to create a python script to find the minimum elevation pixels from an elevation raster (aster,srtm) using arcpy and arcmap 10.1. The purpose is to reclassify these pixels. I have tried but I do not have enough knowledge in scripting. Can somebody please help me ?


QGIS 2.2 Atlas - Blank Export

I've got a map laid out how I want it in QGIS 2.2, using the "Atlas Generation" feature. When I preview the atlas, all 7 pages look proper and seem to work fine. However, I cannot export them to any format as it always results in blank pages (the proper number though, so it appears to be 'iterating' properly). If it matters, it's set to print as raster as I have some transparency. Thoughts on what is wrong?