mkpgm.c : gtopo30 --> pgm download
gcc mkpgm.c
a.out filedir/filename xmin xmax ymin ymax zmin zmax > output.pgm
xv output.pgm
mkgrads.c: gtopo30 --> grads (bigendian) download
gcc mkgrads.c
a.out filedir/filename xmin xmax ymin ymax > output.grads
I. Tamagawa, Feb. 2, 1999
