bug fixed

observation_sim/psf/PSFInterp.py

@@ -366,7 +366,8 @@ class PSFInterp(PSFModel):
 
         if galsimGSObject:
             if extrapolate is True:
-                imPSFt = imPSF
+                imPSFt = np.zeros([ngg+1, ngg+1])
+                imPSFt[:-1, :-1] = imPSF
             else:
                 imPSFt = np.zeros([257, 257])
                 imPSFt[0:256, 0:256] = imPSF