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?