Hello, there, when i tried with trmat, or prmat (the interpolation/kriging function) in "spatial package", i found it it only did interpolation for n x n grid. however, my data is distributed in a rectangle field, not in square, so I would like to set different size for x and y dimension.. HOw can I set it to be m x n grid ( m != n)? ANy hint on how to get around this is appreciated:) yan