Script to decimate the seismic line by keeping every fourth trace.

sioseis << eof
procs diskin gains plot prout end
diskin
   ipath fdm.line6.2x4  end
end
plot
   scalar 1.5E-03 wiggle 0 stime 0 tlines .5 1.
   opath siofil6.2x4 srpath sunfil nsecs 6  ann gmtint anninc 30
   nibs 2859 trpin 300 vscale 1.6667 def .005 clip .01 end
end
prout
   fno 0 lno 99999 ftr 0 ltr 9999 noinc 100 end
end
gains
  type 3 alpha 2.75 end
end
end
eof