gomask − create a masking file
gomask maskfile xname yname x0 y0 dx dy nx ny
Gomask creates a 2D mask with values of 1 on the inside of a convex polygon and bad values on the outside. The vertices of the polygon are specified in counter-clockwise order by the text file maskfile which should have one x-y pair per line with the components separated by white space. The first pair should not be repeated, as this is handled automatically by the program. The arguments xname and yname give the names of the index fields for the candis file. The quantities x0 and y0 give the lower left coordinates of the mask file, dx and dy give the increments, and nx and ny give the dimension sizes.
Dave Raymond