Andrew, These are fascinating images.
Several years ago I tried to convince people that GRB would be a better palette than RGB. I used Cliff's image, your first pattern, and rotated it 90 degrees. If you think of this as the face of a clock, then in an hour the GRB palette goes from white to black in a continuous value from light to dark when seen as a grayscale. Green ns brighter than Red, which is brighter than blue. require 'viewmat' at2=: 13 :'([:{:"1 *.) j./"1 y' RGB=: 255* #:i.8 GRB=:1 0 2{"1 RGB we=: 13 :'<.0++/"1[0.3 0.59 0.11*"1 y' gray=: 13 :'3#"0 we y' RGB viewmat (D=.at2"0 /~ i:500) GRB viewmat (D=.at2"0 /~ i:500) (gray RGB) viewmat (D=.at2"0 /~ i:500) (gray GRB) viewmat (D=.at2"0 /~ i:500) (Another little exercise for JHS) Maybe you'll make some interesting discoveries with your other patterns. Linda -----Origin ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm