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3

You can do this with the Intersect tool. Normally, performing an intersect with polygons will only return the overlapping area. But if you change the output_type from INPUT to LINE, then you can get just the collinear borders between polygons. If this is our input: And we change the output_type parameter: We get the green lines as output: The ...


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Based on your CSV, Tablename: Wahlkreise Column containing value to union on: wahlkreis Other Columns use an aggregate function to grab one of the values (all of them are the same for each district / wahlkreis In the SQL window in CartoDB, type: SELECT wahlkreis , cartodb_id , max(strong_party) as strong_party , max(einwohner) as einwohner ...


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Update: The solution to that particular problem, which got revealed bit by bit, was, that the Memory Layer Saver plug-in had to be installed to make the mask layer, which hides the labels, persistent and gets saved with the project. For those who do not need to use the Mask plug-in but still want to hide particular labels or give them different appearance, ...


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There are a couple of different ways you can do this, and it will vary depending on the software you are using. But in QGIS you can use the Vector Grid tool, which is found in Vector - Research Tools. The tool allows you to set the extent of your working area based on a layer (in your case the polygon layer) and then output either a line or polygon grid ...


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The $x and $y values only work for point layers. Create a layer for polygon centroids and then that will give the x and y values using the $x and $y commands.


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For PostGIS 2.1, you can just convert the geometry to a geography type, where longitudes are always normalised to the -180/+180 range. For example, take these coordinates that are outside the range, and compare the normalised output: SELECT ST_AsText(geom::geography::geometry) FROM (SELECT 'POLYGON((180.12 -16.69,180.00 -16.80,179.89 -16.95, ...


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You can use ST_DumpPoints and iterate over its results. It should be exactly what you're looking for.


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The problem is that something in the stack (QGIS, GDAL, or the operating system) doesn't appear to be handling the ã character in the directory name (so Portimão becomes Portimo). That looks like a bug, which you should check isn't already filed at http://hub.qgis.org/projects/quantum-gis/issues, and if not already filed, add details. In the mean time, I'd ...


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You use this tool to cut out a piece of one feature class using one or more of the features in another feature class as a cookie cutter. This is particularly useful for creating a new feature class—also referred to as study area or area of interest (AOI)—that contains a geographic subset of the features in another, larger feature class. Click on the ...


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If you want to get the distance between two sets of lat/lon, 4326, points, then you can use ST_Distance_Sphere or for more accuracy, ST_Distance_Spheroid. If your fence table is in 900913, then use, ST_Transform to convert, so that both sets of points are in a common SRID. SELECT ST_Distance_Sphere( (select ST_Transform("Fence", 4326) FROM ...


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You can do this with python if you are at least at ArcGIS 10.1. If you have ArcInfo, you can use the Feature to Line tool. Otherwise, you can use this simple script. This script does not support true curves though. The resulting lines, if topologically correct should overlap then you can run an intersect of this line fc on itself to find the boundaries ...


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Seems to be easy, you just need to create the XY coordinate field in your polygone table and later in the script use the arcpy.da.SearchCursor(Poligone.shp,"FieldXY")in something similar to this. Hope this works for you ^^ with arcpy.da.SearchCursor("Poligone.shp",'Field') as Buscador: with open(nombarch2,"a+")as c: for row in Buscador: ...


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The behaviour of gIntersection is not to pass any intersected data by design: Since there are no general matches between intersected spatial objects, any arbitrary operations on attributes require assumptions about unknown user intentions. This is why no data slots should be passed through ... ... The design of gIntesection() is inentional, ...


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I figured this out, you need to refer to an image file, here I have referred to a png I uploaded to cartodb: cartocss: "#layer_name[field='field_value'] {polygon-pattern-file: url(website/image.png); line-color: #9e1e62; line-width:1;} replace the png with the appropriate image replace layer_name with the appropriate layer replace field with the field ...


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I think you have two issues here. The first may be misleading. The warning that you're getting when you start editing is only that--a warning. It means that one or more of the data layers are in a different coordinate reference system than the map's. You can check what's going on by opening the data frame's property page (one method is to right-click ...


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You can. I think your coordinates are flipped. That is usually the culprit. For spatial databases the coordinates are generally x=longitude, y=latitude. So yours puts you somewhere out in the arctic ocean. Try instead ST_GeomFromText('POINT(80.7799 26.8715)')


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You can do a spatial intersection between your two datasets ("Al", "output") with the following code: library(rgeos) inter = gIntersection(Al, output, byid=T, drop_not_poly=T)



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