conv2nan

 CONV2 2-dimensional convolution 
 X and Y can contain missing values encoded with NaN.
 NaN's are skipped, NaN do not result in a NaN output. 
 The output gives NaN only if there are insufficient input data

 [...] = CONV2NAN(X,Y);
      calculates 2-dim convolution between X and Y
 [C]   = CONV2NAN(X,Y);