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2

If you're using a postGIS database, you could use the st_closestpoint function. One argument would be your current location, the other one your inverted circle geometries.


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I don't think that interpolation between points, unless you have really good coverage will work for minerals age. It seems that proximity polygons inside individual areas will do better job. With spare coverage it is worth to consider methods developed by Hutchinson (Australian university), where cotinious raster of something helps interpolate values at XY ...


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That's a good question Philip, I've always used the second method (note it should be ToMapPoint(arg.x, arg.y) as e doesn't appear in the code anywhere!). In the first method you are casting an int to a double and then back to an int which should return exactly the same value... The X and Y (and Z and M) properties of an IPoint are of type Double, the ...


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ST_ClosestPoint will find the closest point on a linestring. For example, locating a point on a road that is closest to a point-of-interest off to one side: SELECT ST_AsText(ST_ClosestPoint(road, poi)) FROM (SELECT 'LINESTRING (10 10, 20 20)'::geometry AS road, 'POINT (14 10)'::geometry AS poi ) AS f; st_astext -------------- POINT(12 12) (1 row) ...


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I went through this last year, and using the OpenLayers basemaps for print-ready exports does not seem to work. I think its the basemap tiles that are moving, and not your points... I would recommend, and you will love the result in terms of quality as much as what you learned, to follow the steps @underdark has put together here: A guide to ...


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If you are running PostGIS 2.0+, you can use the ST_RemoveRepeatedPoints function, so no need to go thru all that trouble of extracting and reconstituting http://postgis.net/docs/manual-2.1/ST_RemoveRepeatedPoints.html UPDATE yourpolygontable SET geom = ST_RemoveRepeatedPoints(geom);


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For this you need at least version 1.3.2 of Shapely, which was released 2014-05-13. The lines of code you are looking at were added in a commit "Allow LineStrings to take arrays of Points".


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This is probably answered in Empty geometries in GEOMETRYCOLLECTION which refers also to http://trac.osgeo.org/postgis/wiki/DevWikiEmptyGeometry. A practical use case for many GIS programs like QGIS which can only hold one sort of geometries on a single layer is to make it possible to import attributes into a new layer and initialize it correctly so it can ...


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Providing you can differentiate between group of points to form a polyline (distance tolerance?), the following works: Find point for which total of distances to other points in the group is maximum. This makes a first point of target polyline (first point in the array) Iterate through the rest of the points to find nearest, add to the array, etc. Convert ...


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add a field, [draworder] calculate the fid into it. Then use it to draw the polylines. BTW ETTOOLs has a good tool for this.



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