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1500 questions
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3 answers

Transfering styles from QGIS to ArcGIS Desktop

We have a QGIS project that has symbols for a lot of different lines. Data comes from a Geodatabase that is accessible to both QGIS and ArcGIS. We now want to use the symbology of the QGIS project to style the features in the ArcGIS map document. My…
til_b
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1 answer

Statistically calculating real road from set of GPS tracks?

I participate in a long-distance cycling club, and we started to collect GPS data routinely from our riders. My interest is to calculate "the real trajectory" for future events based on accumulated GPS data over the same roads. Basically, this would…
heltonbiker
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1 answer

PostGIS: Count number of vertices of lines and polygons in tables

I have 23 tables in a PostGIS schema which I need to count the number of vertices of. The tables are a mixture of lines and polygons so realised I need to use ST_NPoints(geom) So I ran the following query SELECT count(ST_NPoints(geom) FROM…
tjmgis
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19
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1 answer

Creating QGIS Installer for Windows with GUI customization

I'm trying to build a custom QGIS installer for Windows with a stripped down GUI. I customized the GUI using the customization function of QGis and saved it as a .ini file. How can I include this custom GUI in my installer? I found this very useful…
redfrex
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19
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2 answers

How can I calculate the bearing between two points in PostGIS?

How can I find the bearing between two points in PostGIS? Please specify in your answer whether or not the method producing a bearing on the spheroid, or a planar bearing.
fmark
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19
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9 answers

Finding GIS data sources for developing nations?

Not all countries have the benefit of funding/technologies for developing GIS data stores. I'm looking for a list of common GIS data sources that should be investigated when trying to build a good basis for GIS analysis in developing nations (e.g…
Radar
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19
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1 answer

Listing available online WMS services (Weather, Land Data, Place Names)?

I'm Looking for WMS services freely available to the public to overlay on my application, specifically weather and AIS information. Perhaps this is a good place to list some available online WMS services you have stumbled across?
Jamo
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19
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1 answer

Heatmap algorithm to visualise point diversity

Can anyone suggest an algorithm to generate a heatmap for visualising point diversity? An example application would be for mapping areas of high species diversity. For some species, every single plant has been mapped, resulting in a high point…
rudivonstaden
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19
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3 answers

Splitting all lines in layer at vertices using QGIS

I want to automatically split all lines in a QGIS layer at their vertices (like this). I've done a Google search and found this article, which is quite close but the workflow is complicated. Because I'll have to train my co-workers (who are…
Cao Minh Tu
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19
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5 answers

What is difference between FID and OID in ArcGIS platform?

What is the main difference between OID and FID in Esri software?
srikanthrao
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19
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4 answers

Snap lines to points automatically?

I have two vector shapefiles: One file is points representing manholes and the other is a polyline file representing pipes leading to and from the manholes. I need to snap the lines within a specified distance to the closest manhole. Is there an…
GreyHippo
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19
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2 answers

Minimum number of samples for kriging interpolation

I get some data with number of specimens with a request to interpolate it using kriging method. After some investigation it appeared that kriging results (performed in ArcGIS Geostatistical Analyst with default parameters) are not satisfactory.…
Marcin
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19
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1 answer

What User Testing techniques do you use?

In producing dynamic maps for students/users I have found the time invested in user testing well worth it. I use a varient of think aloud protocol called hallway testing. I grab any 2 or 3 likely users for 20 minutes each and set them a sample…
Trevesy
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19
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6 answers

Getting started with GIS Servers on Amazon EC2

Are there any tutorials, talks or presentations that discuss the use of EC2 or other cloud computing services to host GIS Servers? Has anyone had any experience in doing it with Amazon's EC2? How hard is it to setup? I know that ESRI has some…
relima
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2 answers

Adding band to existing GeoTiff using GDAL?

This seems like it should be straightforward but I can't for the life of me figure it out. Given an existing GeoTiff containing a single band, how can you add another band to that GeoTiff? Is the only way to do this to use GDALCreate() to create a…
TheOx
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