calculating raster values over polygon

Discussion created by ilik on Jan 5, 2012
Hi, I have a NDVI raster that has values also over water surfaces.
I am doing some spatial calculations (isectpolyrst in Geospatial Modelling Environment) over the land with buffers that extend over the water. The problem is that the NDVI values over the water will result in a wrong calculation, so I want to set them to zero.
I have a polygon shapefile of the land and water surfaces that I want to use to recalculate the raster values over water.
Is there a way to recalculate / reclass raster values by location in a polygon?