I am working with QGIS (newbie). I have a raster map with 0.5degrees resolution. I created a 0.5degrees width grid layer and I compute zonal statistics from the raster. My problem is that it seems to me that the computed zonal statistics are shifted 0.5degrees, it is, they do not correspond to the actual zones in the raster layer. I think that posting some images will make things clearer: http://imgur.com/a/iaUkx * The grey-scale map is the raster file and the blue-colored map is the zonal statistics displayed as a gradient. As you can see, the blue tiles are shifted one tile to the left.
How can I solve this problem?