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Postgis - Converting 'geometry_dump' data type to a 'geometry' type

I am working with a dataset of property boundaries that has had ST_Union() run on it, thus all the polygons appear as a multi polygon in one row of a table. I would like to separate these out so I get a separate row/polygon for each shape. I have…
Roman Trubka
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Getting layer extent using PyQGIS

I'm trying to write a processing script using grass r.neighbors algorithm for rasters. When you use the GUI for this algorithm, you can leave the GRASS layer extent field blanc to use the minimal extent. On the contrary, when used in the python…
Clement
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How to split non-contiguous feature in QGIS?

I have a shapefile with a feature that is non-contiguous. I want to split the areas on the left from the area on the right. However, QGIS's Split Features tool requires you to draw a line over the feature. When I draw a line between the two areas of…
Evan
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Does Leaflet provide Geocoding service?

I am considering the replacement of Google Maps with Open Street Maps and the Leaflet JS API. Does the Leaflet JS API provide a Geocoding service?
Tahir
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Moving a PostGIS Installation

I have a PostGIS installation running on an old computer that I'd like to move. I spent a bunch of time playing with pg_dump and pg_dumpall without success. It seems the normal dump procedures don't work with PostGIS because file paths get hard…
Seth
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1 answer

Scale 16 bit to 8 bit within range using GDAL

I am looking to scale a 16bit unsigned tiff image to an 8bit image using GDAL (OSGeo4W). However I want to constrain the pixel values so that they stay within the range of the 8bit imagery. What I mean is, I want to ensure the visual proportion in…
Ryan Garnett
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4 answers

Delete points on a polygon using QGIS

I'm new at this, a novice at best. I'm using QGIS 1.7.3. I simply want to select a large number of points on a single polygon and delete them. Is this possible?
Mike Guillen
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Calculating distance to points in QGIS

Is there a way of calculating the distance to the nearest points in QGIS? In ArcGIS Desktop there is a function called Euclidean Distance, which can take an input vector or raster, and generate a raster of distances. I seek a similar function in…
djq
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Meaning of grey and yellow/brown colors of buildings in Google Maps?

I'm wondering what the difference beween those yellowish and the grey buildings is in Google Maps. I marked a few of the yellowish building as an example in the picture below.
Cold_Class
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How do GIS web apps work?

I am completely new to GIS and therefore have questions regarding how the GIS Web development should be made, because the entire concept still confuses me. So, imagine I have a map. And by this, i mean the shape files for the layers and so on. How…
seth
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Finding footprint data for US buildings?

Are there any sources for free and distributable building footprint datasets for major cities around the United States? Ideally, the data would also have the number of stories of each building; is that available as well? I'll give you an idea of…
Jesse Stimpson
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How to change Leaflet Map panes layering order (z-index)?

Leaflet maintains that the Map panes elements contain all layers added to the map. The difference between many of the Map panes is strictly the z-index order of layering. I would like to use a combination of lvector.CartoDB layers, which are…
Michael Markieta
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How do you compute the earth's radius at a given geodetic latitude?

(I see there is an equation on wikipedia that does exactly what I am asking but there is no references. I have no way of confirming the validity of this equation!) I already understand the difference between Geocentric Latitude vs Geodetic…
Trevor Boyd Smith
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API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty while writing the code for assigning projection to…
user1899
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Calculate area for each polygon in R

I am working with a shapefile that has many polygons. How do I add one more field named "area_sqkm" and calculate area for each polygon in the shapefile?
HLe
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