|This routine smears an input matrix nsmear times. This
technique can be used to make discontinuous data suitable for contour plotting.
However, smearing may not yield scientifically correct resultsójust smoother
ones. On output, the smeared matrix is always copied to minout.
The algorithm used is as follows:
1/2 of the value of each grid point remains at the
1/12 of the value of each grid point is placed on the
nearest 4 grid points.
1/24 of the value of each grid point is placed on the
next nearest 4 grid points.
At the borders, ghost points are used so that the integral over the
entire matrix will be preserved.