Unanswered Questions

15
votes
1answer
1k views

Connecting ArcSDE to Quantum GIS for dummies?

I really have a need to be able to connect to and edit ArcSDE data in Quantum GIS. This question has been asked before and apparently is possible, but the instructions are just not specific enough ...
13
votes
1answer
737 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 ...
11
votes
2answers
268 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 ...
11
votes
2answers
1k 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 ...
9
votes
0answers
104 views

Accessing the internal data structure storing Postgis spatial index (PostGres GiST)

I am curious about how the internal data structures and storage mechanism of the spatial GiST index in Postgis. In Oracle, I used to like to show how the SDO indexes were "just another table", and how ...
9
votes
3answers
653 views

Importing KML and style information into Geoserver

So I'm working on a project that's been in development for over a year, but I only recently got involved. My task involves converting roughly 2,500 KML files into another format, importing these files ...
9
votes
0answers
270 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 ...
9
votes
1answer
170 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 ...
9
votes
2answers
889 views

Histogram Matching using Python to improve mosaicking process of multiple overlapping rasters?

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: http://www.idlcoyote.com/ip_tips/histomatch....
9
votes
0answers
243 views

Joining layers with respective elements with PostGIS Topology

I'm currently 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, features ...
8
votes
1answer
67 views

Seeking public database to input date and city to determine country at time and present-day?

I'm looking to automate a common task for us. For example, Jaromir Jagr was born in Kladno in 1972. I want to be able to take that and output a string. Born in Kladno, Czechoslovakia (present-day ...
8
votes
0answers
170 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 ...
8
votes
1answer
187 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 ...
8
votes
1answer
224 views

PostGIS Recursive Query Based on Line Connectivity

I'm having difficulty with a query. I have a network of linestrings, each with a value in the n_type column. This can be one of a handful of options. I'd like to generate a new table that groups any ...
8
votes
0answers
720 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 ...

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