Tell me more ×  I'm looking for a way to join polygons to a
density function for some other feature of interest.  Current
workflow    • make density raster from feature set of interest,
using point/line/kernel density   • sum raster inside output
geometry (for polygons) or just sample it (for points)  This
seems inefficient as I have to calculate a density raster for
many points I won't even use. Is there a tool that does the same
thing but without the raster? This would be like a kernel-
density-aware spatial join, or a kernel density function that
outputs to a preexisting geometry rather than to a raster.
share|improve this question Because most kernel density rasters
are computed using a fast Fourier Transform, and because this is
tremendously faster than a direct calculation (even though it
requires computing an entire rectangular grid of values), it's
likely your imagined approach would be much less efficient in
most applications. For a recent discussion of these issues,
please see…. –  whuber Nov 23 '12