griddata memery issue, use nearest replace linear

observation_sim/mock_objects/FlatLED.py

@@ -129,31 +129,24 @@ class FlatLED(MockObject):
                          cwaves_name[led_type] + 'nm.fits'))
         xlen = flat[0].header['NAXIS1']
         ylen = 601
-
         i = self.chip.rowID - 1
         j = self.chip.colID - 1
-
         x = np.linspace(0, self.chip.npix_x, int(xlen/6.))
         y = np.linspace(0, self.chip.npix_y, int(ylen/5.))
         xx, yy = np.meshgrid(x, y)
-
         a1 = flat[0].data[int(ylen*i/5.):int(ylen*i/5.)+int(ylen/5.),
                           int(xlen*j/6.):int(xlen*j/6.)+int(xlen/6.)]
         # z = np.sin((xx+yy+xx**2+yy**2))
-        # fInterp = interp2d(xx, yy, z, kind='linear')
-
+        # fInterp = interp2d(xx, yy, z, kind='linear')        
         X_ = np.hstack((xx.flatten()[:, None], yy.flatten()[:, None]))
         Z_ = a1.flatten()
-
         n_x = np.arange(0, self.chip.npix_x, 1)
         n_y = np.arange(0, self.chip.npix_y, 1)
-
-        M, N = np.meshgrid(n_x, n_y)
-
+        M, N = np.meshgrid(n_x, n_y)        
         U = griddata(X_, Z_, (
             M[0:self.chip.npix_y, 0:self.chip.npix_x],
             N[0:self.chip.npix_y, 0:self.chip.npix_x]),
-            method='linear')
+            method='nearest').astype(np.float32)        
         U = U/np.mean(U)
         flatImage = U
         if LED_Img_flag: