I'm looking for a simple/efficient way to extract raster statistics from vector file in IDL/ENVI+IDL. Here's my question:
I have a raster image, say temperature, for a country and an administrative boundary shapefile, say state level, with the same projection.
I want to get state's mean temperature from the raster image.
I know I can extract raster image based on vector file and save to another file, and then get stats. However, considering the large number of states, I prefer a more efficient and less space-consuming way rather than saving states' raster image to the disk. For example, get an array of each state based on the query of the state's name?
So anybody has any idea or inspiration to pursue this in IDL/ENVI+IDL?
Thanks a lot.