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If you don't want to write your own code you can use the GDAL Python bindings to do that. Let's say this is your GPS point with lat and lon: from osgeo import ogr, osr # your gps earthquacke point gps_lat = 47.86 gps_lon = 12.66 gps_point = ogr.Geometry(ogr.wkbPoint) gps_point.AddPoint(gps_lon,gps_lat) So your earthquake happens somewhere in the Alps ...


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within arcgis, you can use the zonal statistics as table tool. This will give you a table with the ID of your buffer polygon and the statistics of the raster below. Make sure that you set the pixel size equal to your raster size in the environment setting, otherwise the internal conversion from polygon to raster could be too coarse.


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Okay I figured it out. Make sure the coordinate reference system is the same for both the buffer layer as well as the census block layer. Select Vector > Data Management Tools > Join attributes by location. Set the "Target vector layer" to the buffer layer. Set the "Join vector layer" to the census blocks. Select the radio button for "Take summary of ...


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I think the most likely use of such functions would be to calculate the area of the buffer. Something like: area(buffer ($geometry ,100)) which does not exist, however.


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The field calculator cannot be used in that way. If you want to create buffers, use the buffer tool from the vector menu. The buffer function and other geometry functions in the field calculator can be used for calculations but not to create new geometries/features. For example to check if the features intersect a certain geometry: intersects( buffer ...


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It looks like your urban areas is a Boolean raster. If so, I would vectorize the raster as the simplest means of getting the urban area 'buffer' to match the 'jaggy sprawl'. You can then do a spatial join of the urban points data on your new polygons to provide the polygons with attributes. If the raster is not Boolean and is in fact a grey scale, then ...


1

Not sure what your image pixel resolution is, but you could use the Raster>Coversion>Polygonize tool to convert raster to polygon. The polygon table should have a column representing the color contrast from low to high which you could query to get ride of those features that are black. You could then apply additional analysis on this layer (e.g. dissolve, ...


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Here's some R code that does the job, the caveat being we are in cartesian coordinates. The input matrix coords is a 5x2 matrix of x,y columns, with the last point being coincident with the first point. This is what you get out of spatial objects in R when you read a shapefile, for example. thinrect <- function(coords, factor=1/3){ dx = ...


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I created an ArcGIS Create Custom Grid tool that could be useful for this. However, it might have trouble if any of the rectangles are oriented like a diamond shape. You would set the vertical division to 3 and leave the horizontal to 0. After the tool is ran you need to use the Split Polygons tool in the Advanced Editing toolbar. If you use it, let me ...


3

This can be solved with a model but there are 4 caveats: You need an Advance (ArcInfo) license This model assumes your rectangle is a rectangle so the 2 vertical sides are longer Your rectangle is constructed from 4 vertices only If you want to automate this then all your rectangles must have the same dimensions So after running this model you you are ...


8

I made a custom Create Buffer Interval toolbox for you: http://ianbroad.com/downloads/CreateBufferIntervals.tbx In ArcMap open ArcToolbox, right click in the whitespace and click Add Toolbox. Browse to the one I made and run the Create Buffer at Interval tool. Here's a screenshot of the parameters: It should be pretty straightforward, but let me know ...


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You should look into variograms (look in the documentation under kriging). The variogram indicates the level of cross-correlation between observed features. If you plot the variogram you see it rising rapidly, then tapering off to level (the so-called sill). That would give you a quantitative indication of your "optimal distance". Quite possibly, though, you ...


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You could use postgis. Your output table, "Points_DT_3" in this example, would need to have its geometry column modified to polygon for this example. This example assumes you want 5 buffers, each 10 feet further than the last. DECLARE @ii; CREATE TEMPORARY TABLE temp1 AS SELECT "Shape", objectid FROM tiger."Points_DT_2"; SET @ii = 5; WHILE @ii > 0 ...


4

Aha, I was confused for a while, but now I'm not. Generally, I would expect a buffer in UTM to match up pretty well to a geodetic buffer. Close enough you wouldn't be able to see the difference. But, looking at your map, it looks like you're working in a European city, but you're generating your PostGIS buffer in UTM 18, which is valid in the area of New ...


0

One way is re-use this answer this returns start and endpoint for line , use negative offset for other side SELECT ST_StartPoint(ST_OffsetCurve(center_geom, startpointoffset) as start, ST_StartPoint(ST_OffsetCurve(center_geom, endpointoffset) as end, from xx where yyy this makes line SELECT ST_Makeline(l.start, l.end) FROM (SELECT ...


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you can use the polygon neighbors tools to have table with the neighbours. With this table, summary statistics gives you the numberof neighbours. buffers with two or more neighbors (or with a given overlap) need to be removed according to your example. this can be done using a select by attribute on the joined table.



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