I am using the interpolation plugin in QGIS to interpolate values within a boundary.
I start with two layers; 1) my points and 2) a polygon for the area of interest. Then I go to Raster>Interpolation>Interpolation and add my vector points with the corresponding attribute as an input. I use IDW (TIN does not seem to work for me), set the output file, add result to project, and hit OK.
This creates a raster but it is not the same scale as the point data. Specifically the raster is shorter and narrow (proportionally) than the point data, so the points extend beyond the edges of the raster but the values of those points are represented in the raster. It really just looks like the raster is a little smaller than it should be.
Has anyone experienced this problem? I am not sure what causes it or how to fix it.