12
votes
0answers
264 views

Frequency of overlapping isochrones with map algebra in PostGIS

I have a table of polygons representing travel time isochrones on particular days. For each origin point, there are five isochrone geometries (stored in separate rows). For each origin point, I want ...
10
votes
0answers
671 views

Converting from SLD to Carto CSS?

I have a bunch of layers and corresponding SLD's running a WMS service. I was exploring the possibility of shifting to a TileMill's tile based TMS service. For this, I would like if it were possible ...
9
votes
0answers
150 views

Identifying overlapping time intervals with two more criteria in R?

I have to check birds observations made over a longer period for duplicate/overlapping entries. Observers from different points (A,B,C) made observations and marked them on paper maps. Those lines ...
9
votes
0answers
407 views

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 ...
8
votes
0answers
256 views

Connecting Problem: ODBC versus ESRI Personal Geodatabase (*.mdb)

I try over 2 days to connect an ESRI Personal Geodatabase with QGIS 2.8.1 Here is my testing report. Testing environment: Windows 7 64-bit; MS Office 32-bit; QGIS 32-Bit 1. Step: Creating an ...
7
votes
0answers
140 views

gdalwarp producing empty rasters when called from python script, but not via command line

I'm trying to aggregate some raster data (all .tif) up to a coarser resolution (from .05 degree to .25 degree) using gdalwarp in python, but the command is not working. Instead of getting an output ...
7
votes
0answers
172 views

PyQGIS save raster as rendered image, then use GDAL tools on it

I have tried to use the code from QGis Save Raster as Rendered Image. i is a raster layer: pipelayer = i pipeextent = pipelayer.extent() pipewidth, pipeheight = (pipelayer.width(), ...
7
votes
0answers
103 views

How to access a deleted features attributes (before committing)

I have a signal setup for a feature deletion event on a layer: self.layer.featureDeleted.connect(self.feature_deleted) When I try and grab an attribute from the deleted feature on the slot, a ...
7
votes
0answers
82 views
+50

Output formats for QGIS Heatmap plugin not appearing in drop-drown in Ubuntu

I've been trying to use the heatmap plugin on QGIS (2.8.2) on Ubuntu(14.04) but the drop down for the output formats doesn't get populated. Selecting the drop-down allows me to press OK on the plugin ...
7
votes
0answers
105 views

FLAG - fuzzy landscape analysis in GIS

I am trying to identify wetlands using different topographic indexes, e.g. TWI/CTI. And I would like to try out a method called FLAG (fuzzy landscape analysis in GIS), but I don't really understand ...
7
votes
0answers
175 views

How to extract sublinestring from a linestring with overlapping segments

Problem statement: Given a bus route (defined as a linestring ln.the_geom), and a set of bus stop locations (pt1.the_geom,pt2.the_geom,...ptn.the_geom), divide the bus route into segments between bus ...
7
votes
0answers
125 views

Compute visibility graph on sphere

I have a PostGIS table with some polygons (stored using the geography data type). They represent regions on a spherical earth. For each pair of vertices chosen from among all the polygons, I want to ...
7
votes
0answers
197 views

Joining layers with respective elements with PostGIS Topology

Recently I have started using PostGIS topology extension, but I have some difficulties in understanding how the structure works: One of the key points is the use of "layer"s: as of what I understand, ...
7
votes
0answers
639 views

Modifying File GDB Feature Class Features Using QGIS

I've installed the File GDB API using the OSGEO4W advanced installation when installing QGIS. I've had a bit of trouble with it initially and have posted a few questions with some helpful Stack ...
7
votes
0answers
611 views

Grouping analysis of points to divide polygon into n number of sub-regions using QGIS?

I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg: depth, currents, waves). Briefly, I can create a ...
7
votes
0answers
555 views

Touristic poi-data (api or dump) with popularity measure

I'm looking for freely available touristic (hotel, restaurants, bars, attractions, etc.) poi-data that have some measure of popularity. With popularity I mean, explicit popularity like on ...
7
votes
0answers
120 views

Can I verify that attribute indexes are being used in a query from ArcObjects?

We have some software as part of a larger project written using ArcObjects via .NET. This software migrates and merges data from multiple file geodatabases in one schema to a single file geodatabase ...
7
votes
0answers
633 views

ArcGIS Cost Path Analysis - How Is Arcpy Cost Path Analysis Tool So Much Faster Than ArcObjects

Although I love slinging some python to create geoprocessing scripts/services, I was under the impression that using ArcObjects to do the equivalent operation(s) will have better performance. I've ...
7
votes
0answers
676 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
7
votes
0answers
397 views

How to write a script to square polygon corners?

I'm looking for a script that will square the corners of polygons that are near 90 degrees but not exactly. Near could be dealt with via a variable, for example within 5 degrees of 90 (85 - 95 ...
6
votes
0answers
64 views

Project an attribute from one polygon layer to another

I have 2 polygon layers which can be found here. The two layers are overlapping. The first contains a map of the German counties in 1928 and the second the counties how they are in 2014. The 2014 ...
6
votes
0answers
58 views

QGIS: large .vrt indexing

I have a large number of small tiles merged into a single VRT. The rasters are only viewed at large scale, so only a few of them are visible at the same time. The map refresh in qgis is slowing down ...
6
votes
0answers
84 views

How to display charts next to features in the map?

This question is meant to be primarily on QGIS software but all other software solutions are welcome as far as it is possible to achieve it as easy as possible, preferably out of the box. Though the ...
6
votes
0answers
156 views

Can GRASS compute the line graph representation of an input graph?

I'm interested in computing a line graph for an input graph, preferably in GRASS since I'll be using other GRASS network analysis tools afterwards. I couldn't find any reference to line graphs in the ...
6
votes
0answers
165 views

Spatial query too slow to handle bigger OSM extracts

I'm trying to compute some statistics for OSM data using PostgreSQL 9.3.5 and PostGIS 2.1.4. I started with a small bavaria extract which I downloaded from Geofabrik. The db schema is the normal API ...
6
votes
0answers
214 views

Frontal Detection of sst & Chlorophyll image

I am working on sea surface temperature satellite images and looking for delineating gradients in open source on the basis of temperature. Is there any tool like Cayula and Cornillon front detection ...
6
votes
0answers
120 views

geoserver dxf plugin - howto export attributes label?

i'm trying to export from geoserver a set of layers with WFS request and dxf plugin for dxf conversion. there is an option withattributes:true that have added for each vector layer a ...
6
votes
0answers
704 views

Link QGIS to Anaconda Python Distribution: Spyder, iPython Notebook, pip, scikit-learn

I have Anaconda as my primary Python distro, and want to route Python related QGIS scripts through it. With Anaconda, I have Spyder, can easily install packages with pip, and can launch a iPython ...
6
votes
0answers
139 views

Postgis database query optimisation

I have a set of rasters in DTED format which I load into postgis database using raster2pgsql command line tool. Each of rasters is simply stored in a row and described by rid and a value of raster ...
6
votes
0answers
244 views

ArcObjects : Out of Server Memory when reconciling a large edit session

One of our users has been periodically experiencing Out of Server Memory errors with ArcSDE 10.0 when trying to reconcile a large edit session. VMware ESX Instance: Windows Server 2008 R2 ...
6
votes
0answers
477 views

Printing/exporting WMTS tile layer with desired resolution / zoom level in QGIS

I have a project which uses WMTS and some vector layers in QGIS. I can freely zoom in and out, and tiles are refreshed with appropriate zoom level, just as expected. Now I would like to export part ...
6
votes
0answers
774 views

How to use the linear referencing plugin from QGIS with postGIS data?

I need a guide how to use this plugin properly, I'm a newbie on PostGIS and I'm trying to use the linear referencing plugin of QGIS. I've created a database on postgreSQL with the postGIS extension ...
6
votes
0answers
155 views

Has anyone gotten CartoDB to work on a Raspberry Pi?

I was able to install everything (minus the PPAs and the two node apps) on my Pi that are in the README. I'm wondering if anyone else has done this or if they can help me with the remaining things. I ...
6
votes
0answers
150 views

Add attribute table to a raster in postGIS

I would like to add attributes to a raster stored in a postgis database. I use the following command to insert the raster in the database: raster2pgsql -s 4236 -I -C -M ...
6
votes
0answers
243 views

Why do file geodatabase and SDE readers produce different fme_geometry types?

I have one very simple workbench that I am running against both SDE (9.3) and FGDB (10.0) sources. I noticed two different fme_geometry values for same type of objects. For the first one, i.e SDE ...
6
votes
0answers
208 views

GeoServer pregeneralized layers not working as expected

I've set up GeoServer 2.1.4 and installed the feature-pregeneralized-2.1.4.jar plug in and processed my shape files into each of their separate folders with the generalized shapefiles and I've check ...
6
votes
0answers
406 views

What to do about Geoserver WPS Warning “Could not get a ServiceInfo”?

This is the warning i am getting when i try to use this WPS service from QGIS, and the processing take a long time, but doesn't terminate, what might be the problem? 17 Oct 12:33:25 INFO ...
6
votes
0answers
373 views

Translate Orientation from Sensor data to Geo location

I am tracking a device that might loose GPS signal then and there. And when the GPS signal is too low, I should use the accelerometer and Gyroscope sensors data to guess which way they should have ...
6
votes
0answers
512 views

How to reverse-georeference with QGIS?

I have a map with a "strange" projection (it's basically hand-painted, not an exact one). I can easily georeference it in QGIS using the Georeferencer plugin and the Thin Plate Spline transformation ...
6
votes
0answers
3k views

ArcGIS 10 Rest services regulary stop working

I have a problem with a new installation of ArcGIS Server. The installation is ArcGIS 10 on Windows Server 2008r2 with IIS 7. I have followed this guide to configure the IIS ArcGISServicesAppPool: ...
5
votes
0answers
51 views

Mapping methodology and/or clustering technique needed

I have a scenario in which I have two service centers (A & B) in an area. The capacity of these service centers are different. Service Center A can serve twice as many as Service Center B. They ...
5
votes
0answers
87 views

How to display wind data in R with the leaflet package

I have some data like this : longitude latitude speed direction 1 6.10722222 46.23639 4 360 2 6.95416667 43.54694 4 360 3 7.21472222 43.66556 ...
5
votes
0answers
48 views

rMaps choropleth with custom json

With R I want to make an animated choropleth map with the rMaps package and a custom map. I tried to follow the example of Diego Valle described here and to use the custom map info for Datamaps. ...
5
votes
0answers
98 views

Is there a way to pause WMS layer auto refresh in OpenLayers 3?

I have an application which has to perform a HTTP request (which will handle some map transformations) before fetching WMS tiles from server. Is there a way to pause TileWMS auto-refreshing after ...
5
votes
0answers
74 views

Exotic Projections QGIS

I would like to use some projections in QGIS that I can't see supported directly. An example would be something like this conformal cube projection. ...
5
votes
0answers
52 views

Styling polyline to view which part is above another in self intersection using QGIS?

I need to view a polyline constructed from waypoints of a gps track, that has self intersections in curves, like an exit loop from a highway. I need to visualize it in a way that allow to know which ...
5
votes
0answers
61 views

Interpreting semivariogram high nugget

I made a semivariogram in R using package gstat, variogram() function. I want to see if there is spatial autocorrelation in the residuals of my model (species abundance as a function of habitat, ...
5
votes
0answers
80 views

GeoJson structure

I currently designing a table/document database structure and use GeoJson to store points and routes. Currently I choose MongoDb, I will consider PostGIS later. I want to store route info for public ...
5
votes
0answers
112 views

Setting Field in ArcMap Symbology Properties using ArcObjects?

I am programmatically rendering a feature layer in ArcMap but I can't set the Field property in the Symbology properties form. This results in the layer having the correct render/breaks/legend ...
5
votes
0answers
99 views

How to speed up simultaneous working with PostGIS layers in QGIS?

we are working on one big layer at the same time (10-20 people). Some of us use QGIS 2.8.1 and the other 2.6. The user with 2.8 have a lot of crashes (QGIS). The 2.6 users don't have this crashes but ...

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