function G = rayxgridfZ(F, transla, val)%------------------------------------------------------------------------------% Multiplies gridfunction F with element of stencil given by its value% val and its position transla.% Excess area is filled by padding with zeroes.%% Design and implementation by:% Dr. Paul M. de Zeeuw <Paul.de.Zeeuw@cwi.nl>  http://homepages.cwi.nl/~pauldz/% Last Revision: June 23, 2000.% Copyright 1999-2002 Stichting CWI, Amsterdam.%------------------------------------------------------------------------------o=[0 0];if ~all(size(o) == size(transla))  error(' rayxgridfZ - unexpected dimensions of transla ')endG = val * moveLRZ(moveUDZ(F, -transla(1)), -transla(2));%------------------------------------------------------------------------------