PGM Grayscale Ramps
Try cutting and pasting this into the restricted
Tcl interpreter, or return to the NArray page.
content_type image/x-portable-graymap
set wd 256
set ht 256
narray create pgm -type int $ht $wd
pgm map {
pre { direction = 1; offset = 0; }
if (@0 == 0) && !(@1 % 8) {
direction = -direction; offset = @#0 - offset;
}
[] = offset + direction * @0;
}
puts "P5\n$wd $ht\n255"
pgm map { bio_write("stdout", "c", []); }
(If the first line of the code is content_type foo then the
interpreter will use foo as the content type and not do any special
formatting of the results. Also I had to add the line:
image/x-*; xv %s
To my ~/.mailcap.)
Sam Shen, slshen@lbl.gov
Last modified: Tue Dec 6 20:13:48 1994