Declaration: FillMatrixMasked (var Mat TDouble2DArray; Value: double; MaskArray: TBool2DArray): integer;
The function FillMatrixMasked fills all cells of the matrix Mat which are not masked by the corresponding MaskArray by the value given by the parameter Value. Masked cells are left unchanged. In order to be masked the corresponding cell of MaskArray has to be set to TRUE. The function returns the following error codes:
 0 ... everything is OK
-1 ... size of Mat and MaskArray do not match
-2 ... Mat has no size at all
Hint: Setting MaskArray to NIL is the same as filling the entire MaskArray with FALSE values (i.e. setting MaskArray to nil does not apply any mask at all).