Area of an irregular polygon using side lengths

I have only lengths for the sides of an irregular polygon, can anyone tell me how I can measure the area of the polygon? Remember only lengths of all the sides , no angles or coordinates. Few forums mention about trangulation of the polygon etc But I only have side lengths. Does anybody has any feedback? Thanks.


Save folder connection in ArcGIS 10

In ArcCatalog one has the option to save locations of folders via the "Connect To Folder" button. I have the problem, that ArcGIS don`t save each folder connection which I would like to have in Catalog. Everytime I fail when I want to save the path **U:\GROUPS\GIS\Geo_Data** or **U:\GROUPS\GIS**. Whereas **U:\GROUPS** or **C:\home\data** is no problem. Anyone encountered the same problem?


How to cluster points based on both proximity to each other and proximity to another layer (roads)?

Using QGIS I have managed to created cluster for points based on their proximity of each other (using buffer and spatial joins etc), but I would also like to add another variable to it: proximity to a road (another specific layer). Is there any idea if this can be done with plugins and/or an algorithmic procedure of some sort? Three attached images describe the problem.   1. First image is the points (green dots) that I want to cluster, depending on their proximity to each other and their proximity to a road (black/white lines).   2. Second image is the result I get, which is only one big cluster, entirely depending on the distance between all points.   3. The third image is the result I want: two clusters, separated because of their proximity to the "closest coherent/connected road" I first thought of some solution with adding a buffer on the road layer, but that will probably not work, partly because the road lines are very often segmented. ![image 1](http://i.stack.imgur.com/FmdCS.png) ![image 2](http://i.stack.imgur.com/6weBs.png) ![image 3](http://i.stack.imgur.com/h4rA1.png)


Which software to use for designing city plans?

Which software would you suggest I use for designing city plans? The result needs to be an image (jpeg) so georeferencing is not necessary. I have options like ArcGIS, AdobeInDesign, Adobe Illustrator. I don't know which software is the best for maps like these in example: ![enter image description here](http://i.stack.imgur.com/tZVcC.jpg) Also, I would need to add some 2d effects on the buildings. Thank you for suggestions.


Why can't I open QGIS projects via windows explorer?

We have upgraded from QGis 1.8 to QGis 2.2. Qgis 2.2 is first installed, then 1.8 removed. Since then it is impossible to open .qgs-projects directly from windows explorer. We have checked explorer, file extensions and relinked to C:\Program Files\QGIS Valmiera\bin\qgis.bat . But it doesn't help. We get the error 'qgis_core.dll cannot be found, please reinstall'. But that is rather drastic. I use windows xp.


SLD for OSM data in GeoServer

> **Possible Duplicate:**   >  Standard SLDs for OpenStreetMaps? I can't find a good SLD for OSM. I downloaded the OSM data and imported it to PostGIS. With GeoServer I use it as a data source to create my layers. Is there no open source SLD for OSM out there?


reproject vector layer with pyqgis with new CRS does not worl

In QGIS I am running a script in th python toolbar to export all visible vector layers to a GEOJSON with this snippet:               canvas = qgis.utils.iface.mapCanvas()     allLayers = canvas.layers()     for i in allLayers:               if i.type() != 0 :             print(i.name() + " skipped as it is not a vector layer")           if i.type() == 0 :             exp_crs = QgsCoordinateReferenceSystem(4326,QgsCoordinateReferenceSystem.PostgisCrsId)             print i.crs()             print exp_crs             qgis.core.QgsVectorFileWriter.writeAsVectorFormat(i, '/home/' + str(i.name()) + '.js', 'utf-8', exp_crs, 'GeoJson')      If my vector file has a different CRS it keeps using the vector file CRS and doesn't use the defined CRS EPSG:4326... What am I doing wrong? The whole project context can be found on GITHUB


How to use matplotlib with ArcGIS 10.1 without Microsoft Visual C++ Runtime Error?

I have problems using the matplotlib for python with ArcGIS 10.1 If I run the code below as a script tool in ArcMap. No pdf is generated and when I close ArcMap this error is shown. ![enter image description here](http://i.stack.imgur.com/9NEDb.png) If I run the code from IDLE a similar error is shown for C:\Python\ArcGIS10.1\pythonw.exe but the pdf is generated correct. If I run the code in a cmd prompt no error code is shown and the pdf is generated correct. Does anybody know how to make the script work as a script tool in ArcMap?               from matplotlib import pyplot          fig = pyplot.figure(figsize=(8.27,11.69))          axis1 = fig.add_subplot(311)     axis1.plot(range(10))          fig.savefig('multipleplots.pdf')


Error exporting data from Oracle to shp using ogr2ogr

I have an oracle table which I would like to query/make a selection. I would then like to export the selection to a shp file. I'm using gdal and ogr2ogr. Following the guidelines here and here I have come up with the following:               ogr2ogr -f "ESRI Shapefile" c:/Testing/Scratch/GDAL/symbol.shp OCI:dbusername/db_password@tns_name -sql "SELECT* FROM tablename where VERSION_DATE >= CURRENT_DATE -8" -progress      I then get the following error: "Unable to open datasource 'OCI:dbusername/db_password@tns_name' with the following drivers" There is then a long list of drivers including "ESRI Shapefile". I have now added " after OCI as suggested.               ogr2ogr -f "ESRI Shapefile" c:/Testing/Scratch/GDAL/symbol.shp OCI:"dbusername/db_password@tns_name -sql "SELECT* FROM tablename where VERSION_DATE >= CURRENT_DATE -8" -progress      I no longer get the errors about it being unable to open the datasource with the drivers. I now just get an "Access in denied". I have a working connection to the database in ArcGIS using the same username & password. Does gdal generate its own user?


Ocean flow models - predict the path of an object dropped in the ocean

This question is from a user who wants to calculate the predicted path of a bottle dropped from a ship. He has a spreadsheet of hundreds of these bottles and wishes to display the predicted vs actual landing points of the bottles. Is there a publicly-accessible model which will show the predicted path of an object, anywhere in the earth's oceans? For example, NOAA published a series of maps during the Gulf of Mexico oil crisis, showing the predicted path of the oil spill. I'm presuming that this is a fairly specialised branch of GI-science and the answer will be that such a model depends highly on local variations, the date, wind and other weather conditions, etc. As a next-best option, is information on the general patterns of the ocean currents publicly accessible in a GIS-ready format? It may be possible to create a geoprocessing model from this?


Looking for XSL templates using Google Charts API

Hi all im searching for examples on usage of Arcgis Desktop html popups in general, being more specific on xsl templates using google charts api on it. Any references and comments are welcome. Thanks Jorge Vidinha


Delay on Marker Title in Leaflet

I am trying to put title on leaflet markers. This explains the way to give title to marker which would appear on hover. Is there any way we can set time on that i.e. make the title appear after 50ms of the mouse hover?


Automate import of multiple rasters as layers into tilemill

Could anyone please suggest a way of automating the import of raster tiffs into tile mill? It's driving me mad as I have well over 100 files. I could do it manually but I'm on a tight deadline... I have many warped tiff files ready to be imported as individual layers into tile mill so they can be saved out as a single mbtiles file. Many thanks in advance!


Find out whether geography point lies within geography bounds

I have three points:   * Point A   * Point SW   * Point NE I want to know if Point A resides within the bounds determined by points SW (for south-west coordinates) and NE (for north-east coordinates). I've so far tried both `ST_Intersects` and `&&` to determine this, which works fine for small regions, but fails whenever the bounding area determined by SW and NE points covers more than half the globe. In this case it seems to instead use a different, smaller, bounding area using the same four points. As an example, if I'd want to cover everything from the SW point of South Africa to the NE point of Ireland it would instead catch points where the the NW point is in Ireland and the the SE point is in Madagascar. That is, China would not considered to be within the bounds. Here are some SQL queries to illustrate this:               select      ST_GeographyFromText('SRID=4326;POINT(0 0)') && ST_GeographyFromText('SRID=4326;POLYGON((180 -80,  -80 -80, -80 80, 180 80, 180 -80))') as expectTrue_1,      ST_Intersects(ST_GeographyFromText('SRID=4326;POINT(0 0)'), ST_GeographyFromText('SRID=4326;POLYGON((180 -80,  -80 -80, -80 80, 180 80, 180 -80))')) as expectTrue_2,      ST_GeographyFromText('SRID=4326;POINT(0 0)') && ST_GeographyFromText('SRID=4326;POLYGON((180 -80,  180 80, -80 80, -80 -80, 180 -80))') as expectTrue_3,      ST_Intersects(ST_GeographyFromText('SRID=4326;POINT(0 0)'), ST_GeographyFromText('SRID=4326;POLYGON((180 -80,  180 80, -80 80, -80 -80, 180 -80))')) as expectTrue_5,      ST_GeographyFromText('SRID=4326;POINT(-90 0)') && ST_GeographyFromText('SRID=4326;POLYGON((180 -80,  -80 -80, -80 80, 180 80, 180 -80))') as expectFalse_1,      ST_GeographyFromText('SRID=4326;POINT(0 0)') && ST_GeographyFromText('SRID=4326;POLYGON((1 -1,  -1 -1, -1 1, 1 1, 1 -1))') as expectTrue_5;      I'd want for this to return `t t t t f t` but it returns `f f f f t t`. I've also tried `ST_Intersects(ST_MakeBox2D())` as per the following SO post: http://stackoverflow.com/questions/24212355/query-by-coordinates-takes-too- long-options-to-optimize/24218861?iemail=1&noredirect=1#24218861 I'm using PostGIS 2.1.3 with the `Geography` data type. What functions or approaches should I use to have PostGIS treat my more-than- half-globe-spanning polygons as more-than-half-globe-spanning ones instead of 'optimizing' them to be less? I understand I could just split the bounds in, say, two parts, and check for each, but there must be a cleaner solution.


web map service - does it update by default when data is amended in Oracle source tables?

I have a WMS which source data is held in Oracle. Every year an amendment to the view in Oracle is run to update records. Does the web map service need to be re-published once these amendments are made or are these updates to the data automatically reflected in the WMS? Any help would be appreciated.


How to Geocode a Google SpreadSheet?

I have a spreadsheet in Google Docs with about 20-30 rows, with the following 6 columns : `ID, Name, Address, Cell_No, Latitude, Longitude` where the last two columns are empty. What is an easy way, for a novice user, who is a non-programmer, to geocode the address and populate the Latitude and Longitude fields with result of Geocoding? I just need to populate the Latitude & Longitude fields. I do not need to see any data on a map.


How to color lat/lon points in given RGB data?

I am using QGIS on a Mac. I am working with hydroacoustic data for mapping and interpreting the seafloor. Data are collected, processed and interpreted. The result is a txt file with Lat and Lon in the first columns followed by R, G and B data, e.g. [54.20,7.78,0.94,0.62,0.37]. The files can have 100,000 lines or more. I am not really good in GIS but I need to use it for some reasons. I seem to be unable to plot these data in GIS. There is obviously no symbology/style way to tell the system to take the color values from a file (i.e. the next 3 values in the same line of the file). It is so easy in MatLab: scatter(lat, lon, symbolsize, [R G B]) but I can't work easily with multiple layers in Matlab.


Is it possible to do server-side (WMS) rendering / caching of vector data

I have to develop a webapp that will have to display a large number of polygons on a webpage, with complex filtering options. The source data never changes (I will simply reload a new version of the DB every few months). I will probably use OpenLayers on the client-side. I developed a prototype that drawed the feature as vectors in javascript, but I'd like to switch to server-side rendering for better performance. I could probably do my app connecting directly OpenLayers to a few different WMS layers in GeoServer (postgis backend) with CQL filters, but I have the feeling GeoServer is not very flexible when using a combination of complex filters and dynamic styling of my WMS and the solution could become quite complex. From the developer point of view, a more confortable/flexible approach seems to use GeoDjango and its spatially-enabled data models to generate a dynamic (content and styling) KML file of my data. A (probably naive) elegant solution would be to integrate WMS rendering (and possibly caching) layer between the OpenLayers client and the GeoDjango app that generates KML output. The workflow would be: 1) Openlayers sends user query to "intermediate layer" 2) This layers forward query to the GeoDjango app, get a KML file and render it as WMS and return it to OpenLayers. (alternatively, OL could also talk directly to GeoDjango it sould use a middleware to postprocess its KML result before returning it). As my data almost never changes, I could then benefit from a caching tool such as GeoWebCache between OL and the "rendering layer". I know Google Maps API do server-side rendering of KML files when they are large, but it's a black box tied to their JS library, and I'd really like to do something similar with OL. I've done a few searches, but was not able to find any tool for the "intermediate layer". WMS servers such as GeoServer/Mapserver can use a KML data source, but it seems limited to a static file somewhere in the filesystem, and not from a dynamic URL. Does a tool like this exists ? Or is my approach simply wrong ? Thanks in advance, Nicolas


Performance of Picture Marker Vs Character Marker (font)

We have a point data type to symbolise. The feature classes can often contain more than 6000 points up to 20000. There are about 30 different symbol catergories to these points. My question is what's more performant - creating EMF pictures and symbolising using picture markers or create a font and use character marker symbolisation? We would be using this dataset in both ArcGIS Desktop and ArcGIS Server (silverlight API). Thanks! Rob


ArcPy or FME for adding history to an object?

I have a very specific problem and I'm looking for a solution for it. I need to add some sort of history to an object. The history will be stored like this:   * begin_date   * end_date   * previous_id Suppose the object that I'm wanting to add the history to is X. We have a central database (at the moment all mdb files, we will switch soon to gdb though) that contains the object X with the history. Workers on the field have a local version of the database and they also fill an object X_i that has an attribute changed. X and X_i have an id to track them. Now when we want to merge the local version of the database a script should run and fill the history of the central db like this:               if X_i.changed = true:         search central_X.id, fill end_date with today         search local_X.id, copy this attribute to central_X and:             fill begin_date             fill previous_id with central_X.id             generate new unique id for the central_X      We also add new fields to the central db and update the unique ids:               for every i in local_X:         if i not in central_X:             copy i to central_X             generate new unique id for i             enter begin_date      For deleted items we do something similar but then we set the end_date. At the end of the merge. We create a new X_i where all the ids are correctly filled and the changed attribute is empty everywhere. My question about this is: _I was thinking about doing this in ArcPy or FME because I have some experience with both. What do you think would be best, ArcPy or FME (or something else)._ _Can you point me in the right direction; what are the toolboxes, functions you would use for this?_ I have looked at alternatives like an ArcSDE with archiving, but that would mean we would need to invest in an ArcSDE, change a significant part of our workflow and not all items that we change will have X_i.changed, so the archiving would contain way too much information to be really useful. Edit: added workflow to clarify. ![workflow](http://i.stack.imgur.com/zPA29.png)   1. I can use changedetector for this.   2. If X_i.changed is true   3. If X_i.id is not empty   4. set end_date for all processed data   5. **no idea how to do this**   6. **no idea how to do this**   7. **no idea how to do this**   8. find the biggest id so far and proceed from this id.


How to clear in_memory workspace within ModelBuilder?

I have been using `in_memory` workspace within ArcGIS 10.1 ModelBuilder as part of a workflow to mosaic and clip raster datasets to study area bounds (Figure 1). The model runs fine the first round but crashes the program on the second or third run. I suspect two issues may be occuring: 1) Memory limitation are being exceeded or 2) There is conflict when trying to overwrite temp files `in_memory`. **Is there a way to clear`in_memory` workspace from within ModelBuilder?** Figure 1. ![enter image description here](http://i.stack.imgur.com/gJaRX.jpg) **Edit:** The final model that is now stable ![enter image description here](http://i.stack.imgur.com/zJntN.jpg)


Preventing symbols from different layers from interfering with each other in ArcGIS online

I am tackling a project that contains several new elements for me since I am a high school social studies teacher and not a full-time GIS professional. For this particular project I am trying to show the various US interventions during the Cold War around the world. I have created individual points for each intervention. These points are in a shapefile that contains a list of 49 different interventions. The fields include the country of the intervention, the year, a short description and whether or not a certain type of action occurred. Example: Guatemala, 1954, (description) and the following values for the six types of action possible: Command=1, Troops=0, Bombing=1, Naval=0, Nuke=1, Jets=0. What this means is that in 1954 we used Command Operations, Bombing and Nuclear Threats to intervene in Guatemalan affairs. On this particular point then I would like to see the three distinct symbols for those types of action. Currently I can achieve this by creating 6 layers but the symbols are all stacked on top of each other. This has all been done in Desktop 10.1 Advanced. I plan to create a feature service on our AGOL account once I have solved this problem. Thanks for any advice.


How to Find points in a Kilometre radius

I am new to PostGIS and GeoData. I need to find where the lightning has stroke by a period of time and kilometre radius based on a given location. I have given lon/lat and my table is:               latitude numeric not null,     longitude numeric not null,     time timestamp(0),     geom(point,4326)      I do not know how to use within or radius query. I basically need to find how many points (lightning i have in a radius of a given location(lon/lat). I am using PostGreSQL 9.2 and PostGIS 2.0. Thank you.


Can GeoEXT 1.0 be used along with ExtJS 4.0?

On the GeoExt website their tutorial page has some instructions on how to setup up a application to use GeoEXT. This is the page I am referring to. It mentions that you should download GeoEXT 1.0 and ExtJS 3.2. I have since noticed that Sencha has released ExtJS 4. Can ExtJS 4 be used along side GeoEXT 1.0 without any issues? Or should I go by the book and install ExtJS 3.2? Thanks Ando


How do you Convert a .sp1 file into a Shapefile

I was previously able to convert .sp1 files into shapefiles, but that was last February. I can only remember how to do some of it. How do you convert them into shapefiles ? These are preplot receiver / source points as I am using ArcView 9.3


Finding optimal network with python and network analyst in arcgis 10.0

Hello GIS StackExchange, I'd like to know if there's any way to find the shortest distance across the diagonals of a polygon. I am creating a network analyst solution to determine the most cost effective route between 2 points. The solver will travel along the roads edge for the most part to determine optimal routes but there may be situations where cutting across certain polygon features will be more efficient than continuing along the edge of the road. The question here is what is the best way to cut across the traversable polygon features? ![Sample route optimizer](http://i.stack.imgur.com/gkOK6.png) The image is a sketch i did to illustrate how i'd like the route optimizer to function. The blue point feature is the route origin point while the green feature is the destination point. The green polygons are parcels that can be traversed, while the yellow polygons cannot be cut across. The blue line is the road network which is the main edge feature to determine the optimal route, the purple diagonal(ish) line is the result of the router determining that cutting across the polygon would indeed be more optimal than following the road. The idea i have for cutting across the polygon features is to first determine the shortest distance within all traversable polygons and then create a line feature class containing the shortest distances for all the traversable polygons in the network dataset. This line feature class will then be connected to the same connectivity group as the roads feature class to ensure the router can connect both features and possibly determine that cutting across the polygon is indeed more optimal than following the road edge in certain situations. One problem i have encountered in my research is that polygons may be made up of countless number of vertices and as such it would be difficult to determine the shortest path across the polygon. This question is related to my thesis project, it is to be written in python within arcgis 10.0. I have done quite a lot of research already so don't feel obliged to remind me about the need to learn this for myself because i have and i'm stuck. My biggest fear is designing the model half way only to find out that the approach i took was wrong from the start. That's why i need some help. I'd appreciate any documentation that can help or any complete resource that will prevent me re- inventing the wheel, or even ideas about how to go about certain aspects of building the router. Thanks as always gis stackexchange. Apologies for the lengthy post.


How do I implement a custom IFeatureDatasetExtension?

**How can I implement IFeatureDatasetExtension and register it so that ArcGIS discovers and initializes it?** In arcobjects, I see that Esri has a number of coclasses that implement IFeatureDatasetExtension2. Using Categories.exe, I see there is a COM category called "Esri Workspace Dataset Extensions". ![enter image description here](http://i.stack.imgur.com/QizOF.png) I don't see anything on the FeatureDataset coclass that would let me register extensions, the closest thing is IFeatureDatasetExtensionContainer, but it only lets me access extensions that are already defined. There is no `Add` method.


Trying to use the GeoWebCache "gmaps" service

I am using GeoServer 2.4.5 with built-in GeoWebCache 1.5.0. I'm integrating GeoServer with a Google Maps V3 api frontend, and I got it to work reasonably well using the WMS service. However, I noticed that there's a builtin 'gmaps' service, as described here: http://geowebcache.org/docs/1.5.0/services/gmaps.html I've tried to use it, with a url like:               http://myserver:8080/geoserver/ok/gwc/service/gmaps?layers=ok:OK_Twp&zoom=9&x=114&y=200&format=image/png      however, I get the following response:               This XML file does not appear to have any style information associated with it. The document tree is shown below.     <ows:ExceptionReport xmlns:ows="http://www.opengis.net/ows" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0.0"     xsi:schemaLocation="http://www.opengis.net/ows http://myserver:8080/geoserver/schemas/ows/1.0.0/owsExceptionReport.xsd">     <ows:Exception exceptionCode="InvalidParameterValue" locator="service">     <ows:ExceptionText>No service: ( gmaps )</ows:ExceptionText>     </ows:Exception>     </ows:ExceptionReport>      For some reason, it can't find the 'gmaps' service. Any ideas? I've made sure to enable "Global Services", but can't find any configuration regarding the gmap service in the GeoServer web interfact.


How to offset/displace overlapping lines in a web map?

I have a dataset of points representing a To/From status - something like distribution centres and delivery addresses. When the user clicks on a point I'd like to show the relationships between this point and its related points using lines. Eg when clicking on an address, show the path to the delivery centre. This works fine, except when there are multiple overlapping lines. In this situation I'm looking for a method to separate the lines automatically, so that it's clear there are multiple lines, and each can be interrogated. I've put a simple example on JS Fiddle - this sample creates 5 overlapping lines. Is there any way to displace them automatically, while retaining the start and end nodes? ![enter image description here](http://i.stack.imgur.com/emU4b.png) This is the effect I'm aiming for, ideally handling multiple overlapping lines automatically: ![enter image description here](http://i.stack.imgur.com/Pro8R.png) This example uses Google Maps, but an answer in ArcGIS Server's JS API would be acceptable too.


How to get polyline out of multipart feature using ArcObjects C#

I've got a polyline feature class and I've identified the first feature that is a multipart feature. I now want to find out which of the paths of this multipart feature intersects with a point. Up till now I managed to fill a geometry collection with the parts (paths) of the polyline. My method to check for the intersection requires a polyline input. And this is where I'm stuck. How can I convert/cast/? one of the two paths in the geometry collection to a polyline? Here is some code, but `pPolylineCSPart` is null:               //right polyline into geometry collection     IGeometryCollection pGeometryCollection = new PolylineClass();     pGeometryCollection = pRightPolyline as IGeometryCollection;     //loop through geometry collection     for (int intPartCount = 0; intPartCount < pGeometryCollection.GeometryCount; intPartCount++)     {         IPolyline pPolylineCSPart = new PolylineClass();         //cast polyline part to polyline         pPolylineCSPart = pGeometryCollection.get_Geometry(intPartCount) as IPolyline;         //check if part intersects river         bMultipartIntersectRiver = PolylineIntersectioCheck.Are2PolylinesIntersecting(pPoint, pPolylineCSPart);         if (bMultipartIntersectRiver)         {             pSplitFeat.Shape = pPolylineCSPart;             SplitCSFClass.CopyAttributes(pTransectSplit, pSplitFeat);             pSplitFeat.Store();         }     }      Many Thanks!


What is gin_trgm_ops of postGIS

I am using a query where the following line written               CREATE INDEX trgm_idx ON public.roads_r USING gin (name gin_trgm_ops);      Its returning the following error > operator class "gin_trgm_ops" does not exist for access method "gin" How can I overcome this?


Tracking field personnal using android app and showing in ArcGISonline

Planning to equip field personnel with GPS enabled phones (android) and collect the location and photograph of assets. Can we use ArcGIS for android in the phone, use this to upload GPS and photos , and the use ArcGIS online to show these locations ? Do we need ArcGIS for server or simple we can do it using ArcGISOnline and android SDK ? Adarsh


PostGIS ERROR: function x(geometry) does not exist

I am using the following postgis query for updating a pgrouting table from my custom road data. In the `x(ST_StartPoint(part_geom)) as x1,` line its returning an error mentioned > ERROR: function x(geometry) does not exist               INSERT INTO public.roads_r (     SELECT DISTINCT ON (the_geom)     nextval('public.roads_r_gid_seq') AS gid,     gid AS parent_gid,     name,     no,     type,     NULL as source,     NULL as target,     ST_Length(part_geom, true) as cost,     ST_Length(part_geom, true) as reverse_cost,     x(ST_StartPoint(part_geom)) as x1,     y(ST_StartPoint(part_geom)) as y1,     x(ST_EndPoint(part_geom)) as x2,     y(ST_EndPoint(part_geom)) as y2,     NULL as to_cost,     NULL as rule,     ST_Multi(part_geom) AS the_geom     FROM (         SELECT              a.gid,              a.geom,              (ST_Dump(ST_Union(b.geom))).geom AS part_geom,              a.road_name as name,             a.road_no as no,             a.road_type as type         FROM public.roads as a, public.roads as b         WHERE ST_Intersects(a.geom, b.geom)         GROUP BY a.gid, a.geom, a.road_name, a.road_no, a.road_type     ) AS res     WHERE ST_Contains(geom, part_geom) = true OR ST_Contains(ST_Buffer(geom, 0.00001), part_geom) = true)      Any help will be highly appreciated.


Install shapely for QGIS on Mac

I know there are a number of similar questions, but none of them have answers that allow me to use shapely in QGIS. In particular I am trying to install the Contour plugin, but this fails with the message "The plugin depends on some components missing on your system. You need to install the following Python module in order to enable it: shapely.geometry." The reason for this error is explained well here: How to install the Python module shapely for QGIS use? These are the steps I have taken to solve the issue: I first installed shapely via pip. This allowed me to `import shapely` in python 2.7, which is the default on my system, but installing the plug in still failed with the same error. This question How to install shapely for python 2.6 (Mac) NOT 2.7? explained that qgis uses python 2.6, not 2.7, so I downloaded the tar file and did a ` sudo python2.6 setup.py install`. Now I can `import shapely` in python 2.6 too. But the installation of the plugin still fails with the same warning! I've also tried `import shapely` from the python console within QGIS, and there is "no module named shapely." Is there something I've overlooked? EDIT. Thanks to the comments from gene below, it turns out that QGIS on Lion does use python 2.7, not 2.6. But still it doesn't work. It turns out though that I have a few different versions of 2.7: From the terminal:               $ python     Python 2.7.2 (default, Mar 8 2012, 15:29:59)     [GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)] on darwin     Type "help", "copyright", "credits" or "license" for more information.     >>>        From the QGIS python console:               >>> import sys     >>> print sys.version     2.7.1 (r271:86832, Jun 16 2011, 16:59:05)      [GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.15.00)]     >>>       From the terminal again:               $ python2.7     Python 2.7.3 (default, Oct 22 2012, 06:12:32)      [GCC 4.2.1 Compatible Apple Clang 3.1 (tags/Apple/clang-318.0.58)] on darwin     Type "help", "copyright", "credits" or "license" for more information.     >>>       So it seems that QGIS uses 2.7.1, Apple defaults to 2.7.2, and I also have 2.7.3. So I need to install shapely for 2.7.1?


XML workspace document import missing data

Ok, building on my last post on this topic, export/import from/to SDE. I export my SDE using export "XML Workspace Document..." and I'm using the Z File format because of the large size of the database (exported Z files still approaching 10gb in size). Export process runs successful now, and the import process into a new SDE runs successfully but, when I start checking through all the feature classes, some are missing their data. Schema comes across fine though. Can seem to find any pattern with the feature classes missing data. Truly puzzling. Any help appreciated Thanks


How to calculate volume of bund around pit from TIN and external feature edge

I need to do some volume calculations of bunds. I suppose I should use the Surface Volume tool in 3D Analyst of ArcGIS. Here is the tool description. I am uncertain about the plane height parameter, however. From the tool webpage there is a diagram showing a plane height that intersects the surface. This seems to match our circumstance, where the bund rises above the polygon describing the external edge of the feature, but then dips below the plane of this polygon on the internal face of the bund going down to the base of the pit. Here is the complicated part. The elevation of the external edge of the feature differs. Since, therefore, it is not a perfectly horizontal plane, it doesn’t seem sensible to me to put in an elevation value for the plane height. If a constant value were used, then the bund may not be cut at its external base where the elevation on the boundary varied above or below that value. I see there is also the cut/fill tool. To me this would require a raster of the polygon describing the outer, bottom edge of the bund to be supplied. I'm not sure how to produce a valid raster representing this plane, however. Thoughts?


What are the essential elements of a cartouche, if any...?

I'm trying to design artistic cartouches for some maps that show traditional knowledge locations from specific First Nations in Canada so the cartouche's will reflect their Nation's identity, culture, etc... I'm not having trouble with ornamental features or colours. I struggle trying to fit more modern elements like titles, descriptions, data sources, and maybe even projection/datum information. **Are there some guidelines I should follow when trying to decide what other elements "must" be in the cartouche?** In this case, the audience will be the knowledge holder (person who contributed to the information on the map) so that they can have a hardcopy of their work to share with whom they please. The second set of maps will be for the community showing the comprehensiveness (everyones information) of the study. Possibly displayed on a wall in the community building for example. _Below is a small image of a **simple** cartouche from a historical map I have for those who don't know what I mean:_ ![Cartouche on Klondike Gold Rush Map showing the All Canadian Route](http://i.stack.imgur.com/YUe5U.jpg)


How do you add file name to an attribute field?

Does anybody know how to add the shape file name to a field in the file's attribute table? I've found a description: > 'You have to use inline variable in CalculateField like %Name% in > expresssion so that whatever the name of the file is, the string will be > inserted based on Name of the dbase file !' I've tried to CalculateField tool with %Name%, but I got message:               Executing: CalculateField "2011-11-6 15_41_point" DBFName %Name% PYTHON #     Start Time: Thu Dec 08 23:34:23 2011     WARNING 000405: No records within table     Succeeded at Thu Dec 08 23:34:24 2011 (Elapsed Time: 1.00 seconds)      Where is my mistake?


Datatypes to return in GeoServer WPS

Is it possible, that my created WPS (in Geoserver) returns an image or a pdf (general: returns a datatype, that isn't a supported format by Geoserver). Is it sufficient to expand the ProcessParameterIO class? Can anybody give me a general overview, how to do that?


Advice on choosing ideal software for consultancy

I am taking the step to start a small business consultancy using digital map technology to assist retail business to better understand their environment and make informed location based decision. My focus is retail business and service planning, however, my challenge is the choice of software. ESRI business analyst is not available to the part of the world where i live due to inadequacy of data but i don't want this to deter me from starting the business. I know there is always a way around obstacles if you work at it long enough. While i work on solving the data adequacy issue i want to know if map-info professional will be a good software to purchase (I've never used it before). Any advice?


Intersection of convex polygons on a spherical surface

There are a number of algorithms available for the intersection of two convex polygons, but I am interested in an algorithm to find the intersection of two convex polygons on the surface of a sphere, where the edges of the polygons are great circles. The polygons might be arbitrarily large (i.e. no approximation for small areas). Is there a description of such an algorithm available? Better, is there any Python or C code out there that would do this, and has a liberal open source license or is public domain?


How to treat missing values as null

I have an excel file with missing values encoded as blanks and I want this excel file to be converted into DBF but with the conversion process, the blanks (missing values) become 0. The reason I am doing this is because I want to perform interpolation but because of the missing values becoming 0 the interpolation becomes wrong. My question is how to treat missing values as without deleting the point shapefile and still proceed with interpolation.


Is there any random data generator supporting geometry in PostGIS?

I found few random data generators for PostgreSQL (such as this one), but none supporting PostGIS geometry type, other than point. Making points would be quite easy, but for lines with multiple nodes and for polygons (I need more complex polygons than simple rectangles) it would be hell to write the function myself. I would prefer using others' tools (free and opensource, if possible) instead of making them myself. EDIT: there are algorithms generating random points within a polygon. For polygons, I would prefer a different approach: to generate quasi-centroids first and then make polygons around them. I have some idea how to do it (random starting direction or random angle from previous node + random distance from quasi-centroid). Although if I found a tool generating polygons from scratch, making a centroid or a random point within would be easy. If no one points to any such a tool in a few days, I'll make it myself and post the code as an answer. I don't need complex line generator so much now, so I'll either make it later, or wait for some other answers. Working complex line generators will get at least +1 from me even if I found I won't really need them, and if combined by some good complex polygon generation they should merit acceptation.


Expression based labeling: Look for points in defined radius/buffer

How can I do that with qgis expression based labeling: CASE WHEN _within a radius/buffer of 1km (outgoing from every point with attribute 'place') is a point with attribute 'museum',_ THEN 'M' ELSE WHEN _within a radius/buffer of 1km is a point with attribute 'historic'_ THEN 'H' ELSE NULL END


Is there an opensource way of making 'streetview' panoramas?

I'm interested in making _streetview_ panoramas and am curious if there are any opensource approaches that I should consider for both making and publishing these panoramas. I've been playing with the Android functionality on my phone to make Android Photospheres (using a camera app SDK - here for the curious). These can be published in a streetview-like panorama via Google. This works, and is nifty but it requires Google to approval the panorama for it to be published online. Another approach is to generate my own tiled grid of photos and use the google stretview api: https://developers.google.com/maps/documentation/javascript/streetview#StreetViewOverlays I'd much rather produce these using some opensource tools, so I'm not completely locked into Google. In this interview with Steve Coast from OpenStreetMap, he refers to a device you can put on your phone which will result in _streetview_ like imagery. Is there a recommended way for this imagery be collected, stored, stitched together and shared?


How to synchronize the marker's rotation field with the angular distortion in the map projection

I'm Using QGIS 1.8.0 to plot a global dataset showing the positions of aircraft in flight. The data I have are .csv files with three columns: Latitude, Longitude, and angle of travel. I assign the "angle of travel" column of data to the rotation field in the "Style" tab of the "Layer Properties" dialog window. This works fine except that that the rotation angle does not take into account the angular distortion of the map projection. This means that in places where the angular distortion is high, the flight path looks like a row of dominoes: ![Flight paths in an area with high angular distortion](http://i.stack.imgur.com/grgkb.jpg) Whereas where the angular distortion is low the flight paths looks like a straight line, which is what I want. So my question is: **In QGIS is there a way to synchronise the marker's rotation field** (now called "angle" in QGIS 2.0.1) **with the angular distortion in the map projection?** _EDIT:_ Since posting this question I have started using the new QGIS 2.0.1.   In QGIS 1.8.0 I dont think it was possible to do what I am asking, but in the new version it looks like it is. However, it requires a thorough understanding of the maths behind map projections, which I do not have. In the "Style" tab of the "Layer Properties" dialogue window, when assigning "data defined properties" to the angle of the marker, it is now possible to open an "Expression string builder" dialogue window. ![enter image description here](http://i.stack.imgur.com/ShzE0.jpg) Here, I presume, it will be possible to enter a mathematical equation which modifies the angle of the marker so that it accounts for the angular distortion in any particular map projection. The map projections I am interested in are **mollweide** (or other similar elliptical projection) for a global overview, and also the **UTM zones**. The reasons for my map projection choices are: Mollweide:   I like the look of mollweide for showing global trends. UTM:   To make a complete visualization using all the data and revealing some of the lesser used routes clearly I will have to import and rasterize the data in geographic portions as I don't have enough RAM to deal with the entire dataset in one go.   I was thinking of using UTM zone strips, a bit like a set of globe gore, which I can then stitch back together once rasterized using Geocart. The mercator projection idea below is not ideal as it creates a pronounced narrowing of features near the poles, and there is a fair amount of air traffic in the north.   The conformal projection idea represents a lot more work for me, as many more tiles will be needed than if I use pole to pole UTM strips. So, Im still holding out for someone to tell me at least whether or not it's theoretically possible to type in a formula that will affect all the points in the correct way, if not the formulae themselves. Many thanks


Which Landsat version is appropriate to imply a supervised classification with GRASS GIS?

I need to imply a supervised classification with GRASS GIS to find build-up areas. I want to avoid Landsat 7 images due to SLC problem.   1. Can I use images of Landsat 8 or it's better to use images of Landsat 5?    2. Are images of Landsat 8 full operational or are they in calibration/test mode?   3. Which version is best supported from Grass GIS (6.4 or 7)?


How to get a list of attributes in FME when there are no records in table?

How to get a list of attributes in FME when there are no records in the table? I try use a `PythonCaller` but when there are no records, FME passes over this table. In `PythonCaller` I write:               import fmeobjects     def FeatureProcessor(feature):         print feature.getAllAttributeNames()      Is it possible to get attributes when there is no record?


Dialogue window for ground to grid tool in arcmap 10

I am using ground to grid correction tool with some success but in the window I cannot see all the print. Is there a way to size the window? Does anyone know how to apply ground to grid correction ? For this is self taught and I see the results but not sure if the workflow I am using is the best approach. I am using Arcmap 10 on a network.


Does ArcMap 10.2.1 no longer listen for DELETE key?

We've noticed that in ArcMap 9.3 we could select a feature on the map (while editing of course) and just press the delete key on the keyboard to delete the feature. ArcMap 10.2.1 does nothing when you press delete. If we click the delete button (the X button on the toolbar) it will delete just fine. Did ESRI take away the keyboard event listener? Is there an option we aren't seeing?


How can I access the AddShapefile method in HookHelper?

I'm new to ArcEngine and ArcObjects. I'd like to develop an extension for ArcMap where I have to use `IHookHelper` instead of `AxMapControl`. I am looking for the `AddShapefile` method, which is available for `AxMapControl`, but apparently missing from the `IHookHelper` interface.               public partial class conversionRtoP : Form     {         public IHookHelper phookhelperRtoP;         public IRaster praster;              public conversionRtoP()         {             InitializeComponent();         }              private void conversionRtoP_Load(object sender, EventArgs e)         {             for (int i = 0; i < phookhelperRtoP.FocusMap.LayerCount; i++)             {                 if (phookhelperRtoP.FocusMap.get_Layer(i) is IRasterLayer)                 {                     comboBox1.Items.Add(phookhelperRtoP.FocusMap.get_Layer(i).Name.ToString());                 }             }         }              private void button1_Click(object sender, EventArgs e)         {             Geoprocessor gp = new Geoprocessor();             IConversionOp pconversionop;             pconversionop = new RasterConversionOpClass();                  for (int i = 0; i < phookhelperRtoP.FocusMap.LayerCount; i++)             {                 if (phookhelperRtoP.FocusMap.get_Layer(i).Name == comboBox1.Text)                 {                     praster = (IRaster)phookhelperRtoP.FocusMap.get_Layer(i);                 }             }                  ESRI.ArcGIS.ConversionTools.RasterToPolygon prastertopoly = new RasterToPolygon(praster, outputpathtext);             ESRI.ArcGIS.Geoprocessing.IGeoProcessorResult gpresult;             gpresult = (IGeoProcessorResult)gp.Execute(prastertopoly, null);             int j;             string gppath;             gppath = outputpathtext.Text;             j = gppath.LastIndexOf("\b");             // this is my problem:             ***phookhelperRtoP.(where is addshapefile method)***         }              private void button3_Click(object sender, EventArgs e)         {             SaveFileDialog savedialog = new SaveFileDialog();             savedialog.CheckFileExists = true;             savedialog.Filter = "Shapefile (*.shp)|*.shp";             savedialog.Title = " Save";             savedialog.RestoreDirectory = true;             savedialog.FileName = comboBox1.Text;             DialogResult dr = savedialog.ShowDialog();             if (dr == System.Windows.Forms.DialogResult.OK)             {                 outputpathtext.Text = savedialog.FileName;             }


Geometry Conversion Problem

How do I convert from an ESRI.ArcGIS.Geometry.IPoint to an ESRI.ArcGIS.Client.Graphic point object? In other words, I'm wanting to convert from an IGeometry to a runtime geometry, I guess.


Simplify polygon in OGR

We use ArcObjects pretty heavily and simplify polygons using something similar to the `ITopologicalOperation::Simplify(void)`. No tolerance is passed in as the parameter (it uses the XY tolerance of the associated spatial reference). Now, we're using OGR for some functionality and would like to simplify using this library. What's the equivalent? I'm aware of `OGRGeometry::SimplifyPreserveTopology(double dTolerance)` but I'm not sure where to get the tolerance from the in OGR library.


Add TileCache Schema Layer to Leaflet Map

I am trying to get Leaflet to display a TileCache Schema tileset. One example: http://example.com/tiles/Admin/06/000/000/357/000/000/158.png As far as I can tell, Leaflet only supports TMS style tiling schemas such as: http://a.tile.openstreetmap.org/15/16938/11166.png I tried to find an extension of a L.tileLayer that supports the TileCache tiling schema, but no such luck.


Problem with SPIT (error while importing layers to POSTGIS)

I was attempting to import a polyline roads layer into postgis, using both SPIT in QGIS 1.7 and postGIS GUI for this purpose. I have received errors through both processes as described here:   * SPIT > The database gave an error while executing this SQL: INSERT INTO > "public"."highways"("STREET","FROMLEFT","TOLEFT","FROMRIGHT","TORIGHT","STREETCODE","OBJID","USERID","FJUNCTION","TJUNCTION","LENGTH","ROA... > (rest of SQL trimmed) The error was: ERROR: value too long for type > character varying(31)   * postGIS GUI ![Error msg. from postGIS](http://i.stack.imgur.com/TZAN6.png) What can be the problem and how can I fix it? Thanks for your response. Dor


I need QGIS routing plug-in

I am new to pgrouting. How does it work? What benefits can I get from it? I tried the examples, read some articles, but could not find the QGIS routing plugin for Windows. It is not showing up in the plug-in manager. Finding a route in a given dataset by mentioning a start and end node works, but it is not performing on my local road network shapefile. The query executes, but doesn't show any results. Also it says > Postgres with PostGIS and pgAdmin QGIS with PostGIS Manager and RT Sql Layer > plugins I don't find PostGIS Manager and RT Sql Layer plugins. Have seen osm2po articles, how do they work? What do I do next?


Error while trying to view the attribute table

I have a shapefile which displays fine in ArcMap. When I view the attribute table I get the following error. However the same shapefile loads fine and can view its attribute table to in QGIS. Any ideas ?? ![enter image description here](http://i.stack.imgur.com/ziCSM.jpg)


Downloading Geodatabase to ArcCatalog

I think this is a fairly easy question so apologies. Someone sent me a .gdb in Google Drive. When I download it to my computer, it is a file folder with all the .gdb contents in it. I can't figure out how to add it as a .gdb in ArcCatalog - I know it must be straightforward but I'd be very grateful if someone could explain it to me. Thanks in advance!


Examples of GIS Visualisation

**Examples of GIS Visualisation** [This is a community wiki post, **you are inviting other members of the community to edit it** - not just to correct spelling or improve formatting] Example: Dr. John Snow (1813-1858), a legendary figure in the history of public health, epidemiology and anesthesiology created one of the first uses of geographical analysis on a static map to solve a problem of stopping the spread of cholera through Soho, London, England. ![enter image description here](http://i.stack.imgur.com/L8vfX.jpg) http://upload.wikimedia.org/wikipedia/commons/thumb/2/27/Snow-cholera- map-1.jpg/643px-Snow-cholera-map-1.jpg The first two cholera cases in 1848 occurred in the same room but a week apart at No. 8, New Lane (in red) near Gainsford Street in the community of Horsleydown... water pumps were causing the spread and over a period of time it was found after collating deaths and visualising them. **Good Examples can be ancient, historical or cutting edge.** ![enter image description here](http://i.stack.imgur.com/F2uLN.jpg) source: http://www.ph.ucla.edu/epi/snow/1859map/snowindex.html


Field Calculator decimal places - how can I limit them?

I've added a new column to an attribute table and performed an operation with the field calculator to populate the new column. The result is a column with a percentage. My problem isn't major but I can't seem to limit the number of decimal places so that I just have solid numbers. Right now I have 13 places after the decimal, I would like it to be 0.


Why are the formats of these coordinates different?

I'm really sorry if this is a silly question (and I'm sure it is) but I have tried searching but I am a complete newbie to coordinates and maps and I don't know what I'm looking for so am not finding my answer! I have a gpx file which has coordinates like as follows: > 51 47.322,-2 47.218 > > 51 47.340,-2 47.071 I need to add some new coordinates but I am taking these from google maps,but the coordinates are in a different format. ie: > 51.804979,-2.738793 I know there is a logical reason for this as I've read about different coordinate types, but I don't understand why and what types they are and what I need to do to convert from one to the other? Thanks for any help! Bex


'Select' and 'hover over' features are not working although no error is displayed (openlayers)

On the following html code i get no errors when i check it on firebug. When i select or hover over features i want to see them "highlighted". When i move my cursor onto a feature i can see that something is loading but it is not highlighted. At the same time firebug shows that "post wms" has worked fine and i can see that it retrieves the total size of the feature (Kbs). I can not figure out what the problem is... I am using Openlayers and Geoserver for displaying the shapefiles Code:                                           <title>Welcome to Choros</title>         <link rel="stylesheet" href="http://openlayers.org/api/theme/default/style.css" type="text/css" />         <link rel="stylesheet" href="http://openlayers.org/dev/examples/style.css" type="text/css" />              </style>
Chώros

                 coordinates

             Click on the map to get feature info
           * * * Hello Geographica and sorry for the late reply. When i step through the code line by line i can see that firebug skips the following 2 lines: hover.addFeatures([e.feature]); hover.removeFeatures([e.feature]); As you mentioned before i think that e.feature is not valid. Attached is the image that shows the response that i get from firebug. Can you actually figure out why the e.feature is not valid. I can not see any reason why it shouldnt be. ![firebug Response](http://i.stack.imgur.com/cR83t.jpg)


Registering a SDE Service in 10.1 with Command Line

I am installing ArcSDE on a new development box. I have executed the setup.exe, created an Enterprise database called "GDB123" and created a new sde service called "sde_123". I need some clarification on how to register the service using the administrative commands. The install guide says if your are using dbo-schema register the service with this command `sdeservice -o register -d SQLSERVER,MYSERVER\SSINSTANCE -r SDE_DBA_USER -v sa -i sdesvc` I do not understand what value I am suppose to type in for the `-r` and `-v` options. I think `-r` needs to be the database name "GDB123" but I have no idea what to put for the `-v` option. Heres what I have so far `sdeservice -o register -d SQLSERVER -r ?? -v ?? -i sde_123` How do I make this work? ArcSDE 10.1 install for SQL Server on Windows 2008 RS box Install Guid: http://resources.arcgis.com/en/help/install-guides/arcsde- application-server-microsoft-sql- server/10.1/index.html#/Creating_an_ArcSDE_service_on_Windows_using_the_sdeservice_command/00950000003v000000/ SDE Service Commands Options: http://resources.arcgis.com/en/help/install- guides/arcsde-application-server-microsoft-sql- server/10.1/index.html#/The_sdeservice_command/00950000004m000000/


How to locate events at intersections using linear referencing?

I am having problem in locating intersection crashes. Actually I have intersecting legs with their specified begin and end mileposts. I am trying to locate crashes based on the milepost values. Everywhere it seems fine using arc map 10.1 linear referencing methods except the places where crashes lie exactly in between the intersection legs i.e. exactly on the intersecting point of segments. The crashes are giving milepost based on different leg segment rather than the actual leg. For example in a intersection of street A and B, a crash lies exactly at the intersecting point. The attributes of that crash says it occurred in street A but the linear referencing gives the milepost value based on Street B. Please share your knowledge or ideas if anybody has solution to this problem. Many Thanks!


Stereo Compilation Software with PostGIS

Does anyone know of stereo compilation software that will allow for the writing into a PostGIS database? Both Datum and Stereo Analyst will write to an ESRI Geodatabase. Standard stereo compilation software will write to a DGN, but I am unaware of anything that will write directly into a PostGIS database. Thanks...


Skimage graph route to multiple destinations

I want to route through an array with `skimage.graph.route_through_array`. I have one start point and multiple destination points. I am wondering if it is possible to insert the multiple destination into the function. I know I could also loop over the function, but I am looking for something faster.


How to create/export multiple maps in one layout using ArcMap?

I have an air pollution data that consists monthly mean values of 12 monitoring stations. I made interpolation and want to export the 12 different map in one layout with one legend. Since I am a newbie with ArcMap, I wonder if it is possible. I am using ArcGIS 10.1 for Desktop.


Multispectral image segmentation for natural-resources applications using R

R has the capacity for image segmentation, although all of the examples I have come across utilize a single band for the segmentation (example). I am interested in combining R's capacity for random forest image classification with an object-oriented segmentation approach. What functionality does R have for multispectral image segmentation that is suitable for natural resources-based analysis?


Update Existing Feature Class by Replacing Features with Updated Versions from a Shapefile

I have a feature class in a versioned ArcSDE geodatabase with archiving enabled. I receive regular updates for this data in shapefile format. I want to be able to replace any features that have changed with the new version from the shapefile. How can I do that without recreating the feature class and thus losing my archived history? I have gotten as far as identifying which features have changed, been added, or been deleted. But how to I select all of the features in the existing feature class that have the same ID as the changed/deleted features in the updated data and replace them with the updated features?


PyQGIS esri ascii grid to .bil conversion

Esri ASCII GRID can be converted to esri .bil format by following way in a desktop From QGIS desktop menu-->Raster-->conversion-->Translate(convert format) How can I write a python code because I have 864 esri ascii grid data?


QGIS Sextante Python UnicodeEncodeError

I have some issues with Quantum Gis 1.8. When I try to use shapes to grid (sextante-saga tool) I get the following error (comes up when I try to define the new grid file name): Fehler bei der Ausführung von Python-Code: Traceback (most recent call last): File "C:/Users/Max/.qgis//python/plugins\sextante\gui\OutputSelectionPanel.py", line 94, in saveToFile settings.setValue("/SextanteQGIS/LastOutputPath", os.path.dirname(str(filename))) UnicodeEncodeError: 'ascii' codec can't encode character u'\xfc' in position 19: ordinal not in range(128) Python-Version: 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] QGIS-Version: 1.8.0-Lisboa Lisboa, f440b60 Python-Pfad: ['C:/Users/Max/.qgis//python/plugins\sextante_taudem', 'C:/Users/Max/.qgis//python/plugins\sextantelwgeomprovider', 'C:/Users/Max/.qgis//python/plugins\sextanteexampleprovider', 'C:/Users/Max/.qgis//python/plugins\sextante', 'C:/Users/Max/.qgis//python/plugins\permaclim', 'C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python', 'C:/Users/Max/.qgis//python', 'C:/Users/Max/.qgis//python/plugins', 'C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python/plugins', 'C:\PROGRA~2\Quantum GIS Lisboa\bin\python27.zip', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\DLLs', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\plat-win', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\lib-tk', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\bin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\PIL', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\Pythonwin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\wx-2.8-msw- unicode', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\python\plugins\fTools\tools', 'C:/Tempordner_GIS/J\xc3\xbchnde']


Spatial Join problems in ArcGIS 10.1 - intersect polygon and lines

1. I have hurricane tracks (Lines) and Florida county boundary (polygon) and I want to extract only those hurricane tracks that intersect Florida.    2. In ArcMap 10.0 I used Spatial Join (from Analysis/Overlay) to join the hurricane tracks and Florida polygon map. This created a new shp file of only those tracks that intersected Florida. Importantly it kept the entire length of each of the hurricane track lines that intersected Florida.   3. I have tried repeating this in ArcMap 10.1 using Spatial Join and while it seems to intersect the hurricane tracks with Florida okay - the new shp file does not have the entire length for each of the hurricane tracks - only short bits of lines outside the Florida polygon boundary. Can anyone provide guidance on why this may be the case - it is critical for this exercise to extract the those hurricane tracks intersecting Florida polygon but we need the entire length of each of the tracks for each of these hurricanes.


Four band raster - ColorInterp of the IR band

I have a four band aerial photography raster. The bands contain Red, Green, Blue, and IR data. Using GDALInfo we get something like this currently:               Band 1 Block=2933x1 Type=UInt16, ColorInterp=Undefined     Band 2 Block=2933x1 Type=UInt16, ColorInterp=Undefined     Band 3 Block=2933x1 Type=UInt16, ColorInterp=Undefined     Band 4 Block=2933x1 Type=UInt16, ColorInterp=Undefined      The first three bands can be set to have a colour Interpretation of RGB respectively (GIS' get flaky if they're not set it seems). But what should the **ColorInterp** be for the fourth, InfraRed band? Left `Undefined`? Or is there a setting for IR? Thanks.


Lines as Great circles on a map

How can I get line features to appear as great circles on a map, instead of straight lines? Thanks,


openlayers multiple maps which is used

My page contains multiple OpenLayers map objects loaded in the JS var domWidgetMaps . Each of them with a specific navigation.               var domWidgetMaps = $('div[id^="' + this.id + '"]');     for (var i = domWidgetMaps.length; i > 0; i--) {         var options = {             projection: mercator, //EPSG:3785/900913             displayProjection: geographic, //EPSG:4326             theme: null,             /*                   Lines removed from OL 2.12                 maxExtent: new OpenLayers.Bounds(-20037508.34, -20037508.34, 20037508.34, 20037508.34),                 maxResolution: 156543.0339, //http://wiki.osgeo.org/wiki/WMS_Tiling_Client_Recommendation             */             units: 'm',             controls: [                 new OpenLayers.Control.Navigation(),                 new OpenLayers.Control.PanZoom(),                 new OpenLayers.Control.ArgParser(),                 new OpenLayers.Control.Attribution()                    ],             numZoomLevels: MAX_ZOOM_LEVEL,             allOverlays: true         };             widgetMaps[i] = new OpenLayers.Map(this.id + i, options);         var osm = new OpenLayers.Layer.OSM('osmBackground' + i, '', {visibility: true}, {buffer: 0});         widgetMaps[i].addLayers([osm]);         widgetMaps[i].zoomToMaxExtent();             }      If the user wants to compare several maps, features like: "zoom-in, zoom-out or pan" should be "shared". The easiest solution (I think) is to identify which map I'm working on (How?) and to launch               var bboxSelected = widgetMaps[<SELECTED>].getExtent();     widgetMaps[2].zoomToExtent(bboxSelected);     widgetMaps[5].zoomToExtent(bboxSelected);     widgetMaps[6].zoomToExtent(bboxSelected);     widgetMaps[9].zoomToExtent(bboxSelected);      I tried               $('.map').click(function (e) {     });      It works if I click on the map, but it doesn't work if I click on zoom-in, zoom-out or pan buttons. OpenLayers intercepts the events. How can I get the selected map based on zoom-in/out, pan? Thanks!


How to produce multiple maps with same layout for different layers' extents?

I have an area which is divided into several zones the borders of which I have defined as separate layers. The layers are defined by sql queries on a postgis table of line segments joined with a table that says which segments are part of which zone boundaries. What I want to do is produce a set of maps where each map is a zoom to layer extent for each zone and which has standard header, legend and scale (which will preferably vary with the zone but could be fixed across all maps). My first attempt was to get a new composer for each map -- that worked but was rather tedious. Next I tried producing one map and printing it and then deleting the map frame and going into qgis to zoom to the next layer extent and make the boundary visible then hopping back into the composer to load it in. This worked more or less. Map was fine, legend was OK because it was the same for all the maps and the zone name was easy to edit but the scale needed to be deleted and set up again for each map. Next I looked at Atlas Generation. The manual seems to assume that you know how it works and all you need is a reminder about the details (like so many software manuals ;) It seems to assume that you have something that you are iterating over but I can't see how to make it work -- there is nothing to iterate over to get the layers. Any suggestions welcome!! :) Russell


How to get a composition name in Qgis python console?

In Qgis python console: I want to populate a list with compositions names, like in Composer Manager, but I can't figure out how to get the names (titles). So far:               composerlist = self.iface.activeComposers()       And I get a list of `QgsComposerView` objects. Now I want something like that:               for item in composerlist:         print item.title()        ![enter image description here](http://i.stack.imgur.com/c2qwi.jpg) Thank you.


qgis how to split a field into field1 and field2 - comma is separator

How to split a field into field1 and field2 - comma is separator in field? Tryed to use field calculator /Jan


Can you set a QGIS print composer to render the map as default?

I have set up a number of templates for the print composer in QGIS. In the Print Composer, there is the option to have the map image displayed in 3 ways:   * as a blank rectangle with no updates until it is output    * as a manual refresh based on cache    * as a rendered refresh When my templates are opened, the map image loads as a blank rectangle by defualt, is there a way either in QGIS settings or in the template itself to force the map image to load as "Cache" or "Render" without having to manually change this?


What's wrong with my expression to control label colors?

I am struggling to alter the label colours according to field values (as strings) in the attributes table. In my mind what I want is: If the string in column X = 'Proposed' Then label the point using the string in column Y, with color A Else Label the point using the string in column Y, with color B End I have tried a bit, but struggling with the syntax               case when  "ownerenc" = 'Proposed'      then  (color_rgb(256,256,256))     else  color_rgb(56,56,0)        end      But I realise this is quite wrong! Many thanks for your suggestions.


How to use inbuilt tools in QGIS Modeler?

Is it possible to incorporate inbuilt tools like, for eg: vector grid of Research tools in QGIS model builder ?


Restrict the scale of the search widget in ArcGIS Flex API

I wonder if I could restrict the scale scope only for the searching widget (and not the extent of the map)? We want to narrow down the scale for searching in order to avoid too many results which may cause intranet traffic jam. I am using Adobe Flash Builder and ArcGIS Server 10.2.2.


Raster export for regressions analysis

I have the following issue: I am trying to do a regression analysis between the (z) values of two rasters. What I would ideally like to have is the raster output not as grid but rather a list of x1y1z1 x2y2z2, x3y3z3,... Is there a way to do this easily?


Coordinate System (Malaysia RSO Projection) not lining up in QGIS and ArcGIS for Desktop?

I am using QGIS 1.9.0 on Linux Mint; and I am new to (Q)GIS I have three layers (2xshapefiles, 1xopenlayer[Bing Maps]) that I am trying to line up located in peninsular Malaysia. **Shapefile_1** is a subdistrict border (WGS84; EPSG:4326) **Shapefile_2** is river system within the subdistrict (GDM2000 Peninsula RSO; EPSG:3375) **Openlayer** (set as the ProjectLayer CRC; WGS84 Pseudo Mercator; EPSG:3857) When importing the layers in QGIS, Shapefile_1 is close to the borders of the subdistrict shown in the Openlayer -- but clearly not matched. Shapefile_2 is incorrectly located hundreds of kilometers north east off the coast. Whe the same layers, with the (apparently) same CRC information are displayed in ARCGIS, they line up correctly. Any insights would be greatly appreciated.


Zonal Statistics-Weighting

I have a raster file on precipitation and I want to create zonal statistics as a table using a shape file wiht boundaries of countries across the world. However it appears that I need to take into account that in different latituted the corresponding area is different and thus I need to weight my statistic (mean etc) for area. Any suggestions on how I can do that? Thanks!


Loading geotiffs into PostGIS using raster2pgsql

I have an issue with loading some Ordnance Survey raster data into PostGIS. I have been using the following raster2pgsql command to load a tif that I have placed in my C:\Program Files\PostgreSQL\9.1\bin folder into PostGIS:               raster2pgsql -s 27700 -t 5000x5000 -I -C -M  *.tif  > os_strview.sql      I then execute the follwing psql command:               psql -h localhost -U postgres -d raster_test -f os_strview.sql      This works fine but when I tried to view the data in QGIS I could only see the raster_columns table in the selection box when trying to add a PostGIS layer. I tried using the plugin Load raster to PostGIS instead. This works but my raster image had no colour. I then saw this post. I used the Raster > Convert > PCT to RGB technique to convert a single tif to a geotif. Unfortunately though when running the psql command above I get this error message: C:\Program Files\PostgreSQL\9.1\bin>psql -h localhost -U postgres -d raster_test -f os_strview.sql BEGIN psql:os_strview.sql:2: NOTICE: CREATE TABLE will create implicit sequence "sx03 nw-geo_rid_seq" for serial column "sx03nw-geo.rid" psql:os_strview.sql:2: NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "sx03nw-geo_pkey" for table "sx03nw-geo" CREATE TABLE psql:os_strview.sql:3: ERROR: could not load library "C:/Program Files/PostgreS QL/9.1/lib/rtpostgis-2.0.dll": Invalid access to memory location. LINE 1: INSERT INTO "sx03nw-geo" ("rast") VALUES ('01000003000000000... ^ ROLLBACK I take it this has something to do with the size of the geotif I'm trying to load into PostGIS - which is 71 MB! Is there another method I should be trying? What is the limit on the size of a single image you can load into PostGIS?


How to create a grid constrained within a polygon in QGIS?

In QGIS I have created an irregularly shaped polygon. I can create a grid based on the maximum extents of the polygon via `Vector>Research Tools>Vector Grid`. However, what if I need the grid to only be displayed inside the polygon's boundaries? How can I create a grid within a polygon in QGIS?


How to create a polygon (fixed width buffer) around a polygon in QGIS?

I have created a polygon in QGIS (in this case it describes a country's maritime baseline). I need to create a second polygon whose boundary is a fixed distance from the original polygon. (in this case I need to create the territorial sea boundary, which lies 12 nautical miles outside the baseline). I think geoprocessing tools>buffer is correct tool for this job? But I can't figure out what units QGIS uses for the `buffer distance`. What should I enter in `buffer distance` to generate a 12nm buffer?


GDAL: C++ API to Convert Text file of Coordinate points to Raster Pixel line?

I am using GDAL to "Grow" areas form starting seed points. I have a text file listng the coordinates of my seed locations. The X,Y coordinates are in the coordinate system of a raster image. I want to burn these point locations into the raster image. I don't kow how to convert my point coordinates to the proper raster image pixel/line locations. I have the geotransformation of the image. I see GDAL classes in the API tutorial that return transformed coordinates from image row/col locations but not the reverse. I am famialiar with the utility that does this, but I don't see a C++ programmers API to do this. Does anyone know how to do this? This capability is fundamental to what I'm trying to do. Thanks in advance for any help you can offer.


Get Web Map Layer Field Value for If/else Statement

I've been trying to read through the ArcGIS JavaScript API but can't find what I want. I have a web map on my page that is based on my my map stored on ArcGIS online. I want to create an if/else statement that does different things based on the value of a field in the layer. But I'm having a hard time accessing the field of the layer I want. Here is part of the JavaScript in my HTML code.               var exLayer = actualmap.getLayer(actualmap.layerIds[6]).layerInfos[0];         console.log(exLayer);      With the code above, I am able to access the layer I want in my web map. The web service I want is number 6 on the map, and the layer I want on this web service is number 0. I'm trying to access the field in layer 0 called "TID", and I want to get the rows with "TID" > 0 and rows "TID" = 0 for my if/else statement. I tried the below, but it didn't work. It just gave me the layer name.               var test1 = Field(exLayer).name;         console.log(test1);      Any suggestions?


Why is QGIS not launching?

I've got a problem using qGIS. Always when I try to launch the programme with the desktop icon, nothing happens. I also checked the Task Manager and it doesn't show any process running regarding qGIS. * * * @yalestar: The target field shows this: "C:\Program Files\Quantum GIS Lisboa\bin\nircmd.exe" exec hide "C:\Program Files\Quantum GIS Lisboa\bin\qgis.bat" @Sven: I don't think that's the case, as I don't get any error message, but I'll give it try. * * * @Underdark: I had Microsoft C++ 2008 already installed, so I launched the installer and selected to repair it. However, qGIS still isn't launching. @Sven: I've tried your soulution, but qGIS still isn't launching. @mapoholic: Nope, I'm using Vista 32-bit. * * * @Andre Joost: I've tried to launch it manually, but then I get an error message telling me, that qgis.bat couldn't be found. I don't have any .qgs files on my PC, so I can't test it. * * * @M P: Thank you for the help. :) However, I can't find qgis.bat in the bin folder. But there's a file there called 'qgis.bat.tmpl'.


Historical Hurricane Tracks

I have found a great source for historical hurricane data, but I can't seem to find a way to download the track information. It appears that you can only view the data on the website. I was wondering if anyone else has had this issue, and if anyone knows a way to get access to the data (either as a .shp or .kml). Here's the website: http://www.csc.noaa.gov/hurricanes/# Thanks... * * * Yes I did see this, I was hoping there was some data already made. Wishful thinking. Guess I will make the files. Thanks...


Create point between two points with given distance or length

What I have:   * Coordinates of Point A and Point C and therefore vector and azimuth from A to C What I want:   * Coordinates of Point B (between A and C) with a distance from A to B of 35.2 meters.   * Suppose to work in every coordinate system Some code:               import shapely.geometry as g     line = g.LineString([(0, 0), (0, 100)])       print line.interpolate(35.2).wkt      ..works in UTM 32N but not in geographic coordinates?!


Consuming secured ArcGIS for Server services in Google Earth?

I am able to easily consume unsecured ArcGIS for Server (AGS) services in Google Earth (GE), but not secured services. I have created a KML Link in AGS Manager with no luck, and added the service manually as a link in GE with the same result. The service is added to GE but a red circle is displayed when the service refreshes. Has anyone been able to do this successfully?


Openlayers - Many broken tiles with vmap WMS in EPSG:900913

I would like to use the vmap WNS (http://vmap0.tiles.osgeo.org/wms/vmap0) in an OpenLayers map. I encounter many broken tiles (pink) when using the srs: EPSG:90013 contrary to EPSG:4326 and that at every zoom level. ![enter image description here](http://i.stack.imgur.com/GXlUM.png) I would like to know what could be the cause(s), and if it's a problem on the server side or on the client side.                 map = new OpenLayers.Map('map',                 { projection: new OpenLayers.Projection("EPSG:900913") });            openL = new OpenLayers.Layer.WMS( "OpenLayers WMS",                     "http://vmap0.tiles.osgeo.org/wms/vmap0", {layers: ['basic','stateboundary','coastline_01'],                                         srs: 'EPSG:900913',                                       isBaseLayer: true                                       });       map.size = new OpenLayers.Size(1000,800);       map.addLayer(openL);       var bounds = new OpenLayers.Bounds.fromArray([-180.0, 90.0, 180.0, -90.0]);       map.zoomToExtent(bounds.transform(source,dest));


What does property FeatureTypeName do in Styled Layer Descriptor (SLD) specification?

I am studying the Styled Layer Descriptor (SLD) specification. I got a general grasp of how I can use it to style a map. I still have one question about the FeatureTypeStyle though. When looking at the FeatureTypeStyle I see the property FeatureTypeName. What does this do? Say for example I got a layer called 'Rooms' and every room has a door (line) and figure (polygon) could I use the FeatureTypeName to say I only want to draw the doors?


When is an address in a new subdivision available for mail delivery?

I have customers that are complaining that some addresses validate on the USPS validation site (https://tools.usps.com/go/ZipLookupAction!input.action) but my geocoding vendor can't geocode the address. Google Maps shows recent construction in the area, so I'm guessing that the underlying data for the geocoding vendor is out of date. However, I'm wondering why the postal address is valid. What is the process by which the USPS validates addresses in new subdivisions?


using raster calculator

I have a combination method to combine two raster( raster x and y) . the method is : x+y / 1- min(|x|,|y|) my problem is about "," character .whats the "," means in the method and how can i use this method in raster calculator ?


ArcGIS Engine, How to change IMarkerSymbol size in runtime?

I'm using ArcGIS Engine 10 with C# Winforms to visualize some elements on a globe control. All elements are of type `IMarkerElement` which have symbol of type `IMarkerSymbol`. Now I want to add two buttons to increase/decrease element's size. I tried this two methods with no success 1.               ((element as IMarkerElement).Symbol as IMarkerSymbol).Size = newSize;      2.               ((element as IMarkerElement).Symbol as IMarker3DPlacement).Size = newSize;      I noticed that I can't change `IMarkerSymbol`'s properties values after creation (like size, offset, depth, ..etc.)? How to change this values?


How can I mosaic raster data which have different number of bands ( 3 and 4)?

I would like to mosaic 100 raster data. several raster data's band are 3, though last data have 4 bands. How can I mosaic raster data which have different number of bands?? If somebody knows how to solve this issue, let me know. OS:Windows XP GIS: ArcInfo 10.1 or QGIS1.8.0


How to interpret this pgRouting shortest path result?

I am trying to use pgrouting's shortestpath function. It returns a set of edges for the shortest path. However, the start node of the next edge is not the end node of the previous edge. I mean they are not connected. So while displaying I am joining the end node of the first edge to the start node of the next edge. However, I am seeing that the coordinates are repeating. I am not sure why, For eg plotting just the coordinates of the start and end node of each edge, I have something like this:               start end     A     B      C     D     A     E      As you can see the coordinates are repeating like A,A in the previous case. As a result there are lots of lines crossing over. Any suggestions or clarifications?


Display a georeferenced DEM surface in 3D matplotlib

I want to use a DEM file to generate a simulated terrain surface using matplotlib. But I do not know how to georeference the raster coordinates to a given CRS. Nor do I know how to express the georeferenced raster in a format suitable for use in a 3D matplotlib plot, for example as a numpy array. Here is my python code so far:               import osgeo.gdal     dataset = osgeo.gdal.Open("MergedDEM")     gt = dataset.GetGeoTransform()


Which is more efficient process in ModelBuilder - Merge/Dissolve or Union/Diissolve?

I'm creating a model which combines four very large files and dissolves them. At the moment, my workflow uses the Merge tool and then the Dissolve tool. However, I was wondering if using the Union tool and then dissolving would be more or less efficient. I don't need to maintain attributes for my purposes. I just need to create a layer which contains the geometry. The feature classes may overlap each other, and they may also contain overlaps within themselves. As the end result is the same, does anyone know which process would be more time efficient? Below are screenshots of my workflows: Merge then Dissolve: ![enter image description here](http://i.stack.imgur.com/JvI3o.jpg) Union then Dissolve: ![enter image description here](http://i.stack.imgur.com/02r0A.jpg)


Level of data available on FactFinder

I am trying to find data at the block level or even block group level for the SF1 files and ACS 2010 or 2009. Just recently, two months ago, I was able to get this data but for some reason I am now only able to get it at the census tract level??? I have followed all the ways in which I am suppose to extract this data. Did this change?


Comparison of metadata styles available in ArcGIS

I'm looking for an overview of the differences between the editable metadata styles available in ArcCatalog. Were the diferent styles developed for use by specific groups of users? Are there any advantages/disadvantages of using one style over another? What are the specific differences in the available fields? Complete answers to these questions might be too lengthy for this forum. A few sentances with links to pertinant resorces would be a great help. The ESRI help is severely lacking in this area (unless I've missed something). I'm using ArcGIS 10, which seems to have fewer options than earlier versions had, so I'm mainly interested in the four options built into ArcCAtalog, plus the FGDC editor add-in. However, more is always better. Thanks.


How to debug "msProcessProjection(): Projection library error. no system list, errno: 2" error in mapserver?

I think I have a misconfiguration in my mapserver that is preventing it from serving up imagery. In my map file, I have this section:                 PROJECTION         "init=epsg:4326"       END      If I leave that section in, I get this error when calling `GetMap` or even `GetCapabilities`:               msProcessProjection(): Projection library error. no system list, errno: 2      If I remove that section (not desirable), `GetCapabilities` works, but `GetMap` gives this error:               <ServiceExceptionReport version="1.1.1">         <ServiceException code="InvalidSRS">msWMSLoadGetMapParams(): WMS server error. Cannot set new SRS on a map that doesn't have any projection set. Please make sure your mapfile has a projection defined at the top level.</ServiceException>     </ServiceExceptionReport>      Which is expected because I just removed the section. So, my question is how do I debug the error: `msProcessProjection(): Projection library error. no system list, errno: 2`? Searching online, I see comments related to permissions, but apache (user running httpd) can access the following directories defined in my httpd.conf:               SetEnv LD_LIBRARY_PATH /some/place/lib/     SetEnv PROJ_LIB /some/place/share/proj/     SetEnv GDAL_DATA /some/place/share/gdal/     SetEnv LC_NUMBERIC C     SetEnv GEOTIFF_CSV /some/place/share/gdal/     SetEnv LANG=C      In `/some/place/share/proj`, there is a file `epsg` that is as I expect. I get no errors from apache.


How to reproject base layers in QGIS once open layers are removed?

I recently discovered the wonders of the osm maps. however now all my projects have all gone curved. is there a way to go back to how they were set originally. opposite to this question: How to reproject base layers in OpenLayers? So basically how to reproject base layers once open layers are removed.


ArcGIS constantly shut down by itself

I am trying to open Census tract data, downloaded from http://www.census.gov/geo/maps-data/data/tiger-data.html Every time, I open the file in ArcGIS, the software will return an "serious application error...unable to continue" and close by itself after a few minutes. Does anyone have the same problem, or know how to deal with it? I have tried different computers, different state's file, and redownlaoded files... Thank you!


Is it possible to link polyline features on a web map to a Google Chart?

I would like to display a line chart and (leaflet) map beside each other on a web page. When I turn off a series on the chart the associated polyline feature (river) should turn off on the map. I am having trouble finding examples of this functionality. Is it possible?


How to use pgRouting (pgr_drivingDistance) with GTFS?

I used gtfs2pgrouting to import gtfs data in postgresql, then I have these tables               List of relations      Schema |    Name     | Type  |  Owner        --------+-------------+-------+----------      gtfs   | agency      | table | postgres      gtfs   | calendar    | table | postgres      gtfs   | frequencies | table | postgres      gtfs   | routes      | table | postgres      gtfs   | shapes      | table | postgres      gtfs   | stop_times  | table | postgres      gtfs   | stops       | table | postgres      gtfs   | trips       | table | postgres     (8 rows)      (several tables as "shapes" are empty) But is it possible to use pgr_drivingDistance on this or is it another way to do it? My goal is to create isochrones Thanks


How to store both fixed and variable attributes as a feature class?

I have a live data feeds as an XML file from the Internet. I need to use Python and ArcPy lib to store each feed as a point feature in a feature class of an ArcSDE datbase. The xml looks like:               <array-list>         <spider-pos-wSVO brigade-no="36145" heading="280" altitude="302" longitude="146.09046833333332" latitude="-37.054605" personnel-no="0" speed="13">             <attrA>12</attrA>             <attrB>0</attrB>         </spider-pos-wSVO>         <spider-pos-wSVO brigade-no="36145" heading="280" altitude="302" longitude="146.09046833333332" latitude="-37.054605" personnel-no="0" speed="13">             <attrA>12</attrA>             <attrC>0</attrC>         </spider-pos-wSVO>         <spider-pos-wSVO brigade-no="36145" heading="280" altitude="302" longitude="146.09046833333332" latitude="-37.054605" personnel-no="0" speed="13">             <attrA>12</attrA>             <attrD>0</attrD>         </spider-pos-wSVO>         ....     </array-list>      Obviously each element has a fixed set of attributes (heading, altitude, longitude and latitude, etc etc) and a various set of child-elements (attrA, attrB, attrC and attrD, etc). I am able to store the fixed attributes as attribute fields in the SDE feature class but have no idea how and where to store the variable ones. Has anyone got a best practise for it? Thanks


Are US Census tracts GEOID the same across different years?

I want to know if it is appropriate to join tables from different years to the same census tracts TIGER file. Do all census tracts' ID stay the same? How would they change--adding new tracts, modification, merging, etc. ? Thank you! S.


Manipulating Azimuthal Equidistant Projections in QGIS

I have a shapefile of world countries that is projected as Azimuthal Equidistant with Chicago, USA as the center. I would like to change the projection such that Edinburgh, UK is the center. One would think that this should be as simple as changing 2 numbers in the coordinate system parameters... The problem that I seem to be experiencing is that QGIS makes it difficult if not impossible to view the complete proj4 code of a given shapefile's coordinate system parameters. This is what I have tried so far:   * Added shapefile of world countries projected as Azimuthal Equidistant with Chicago as the center   * Opened properties, metadata tab, copy proj4 parameter code   * Went to settings, custom projection, paste in proj4 code, changed the lat/lon from that of Chicago to that of Edinburgh   * Saved shapefile of world countries, specified my new custom projection, added new file to map   * My new file looks like a map of Pangaea, with the continents all smushed together. I think there must be other parameters aside from those shown in the proj4 code of the metadata tab. The only thing I'm changing in the proj4 code is the center of the map, but the change I'm seeing is much more than that. My observation suggests that more than one independent variable is changing. I would be happy to send my shapefile to anyone who would like to play with it. Thanks, Daniel Wolf Environmental/Geospatial Enthusiast