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I have point data of population density that I have plotted to show density with proportional circle symbols. This is straightforward with many ways of achieving this in different software and packages. But I would also like to use colours to show not only density by proportional symbol but also have the proportional symbols coloured to represent different values from another map layer, a raster map.

So for example, I want the largest symbol size to be coloured red, orange or yellow depending on the value of the spatially corresponding raster cell. So each symbol size will have different colours depending on the raster.

Is there an existing R function that does this (I cannot find one)? Or is there a way of clipping the (coloured) raster map by a point map that is displayed with proportional circles?

marked as duplicate by Jeffrey Evans, Andre Silva, Evil Genius, PolyGeo Mar 21 '16 at 21:23

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First thing is that you need the informtion of the raster-cells in your vectorgeometry, as you want to use them for the symbols. Depending on what software you can use it is easy in ArcMap (with spatial analyst) to use the tabulate area tool to create a table with the raster-values for each of your points. This table you can connect to you original points. Then you can use the "multiple attributes" Symbology to create the combinations of your color classes and symbol sizes. Should look like in the picutre below.

Not sure if this helps you, but you tagged ArcMap as well, so this might work for you. Within R i would try the intersect or extract function from the raster package to get the needed values.

small example with some random numbers

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