Question:

How can I produce a plot with both colors and patterns?

Example:

Explanation:

Colors and patterns can both be used by using the /LEVELS qualifier to specify different sections of the data to be plotted.

fill/levels=(top half) data
fill/over/levels=(bottom half)/pal=black/pat=pattern data

The tricky part comes in getting the shade key correct on the right hand side. To get it right it's helpful to use the PPL SHAKEY command and the following symbols defined by plot plus (the graphics package underneath Ferret).

Note: These symbols are only defined after an initial plot is produced.

PPL$XLEN

horizontal axis length in inches

PPL$YLEN

vertical axis height in inches

PPL$XORG

horizontal axis origin

PPL$YORG

vertical axis origin

The PPL SHAKEY command is described in the shade key FAQ.

Solution:

The graphic above was created using the following script:

use coads_climatology
set region/l=1
shade slp
show sym/all
message "Using the symbols above we create some variables for the ppl shakey command."

let ylo = ($ppl$yorg)
let ymid = ylo + ($ppl$ylen)*3/5 

! 1010 is 3/5 of the way between 980 and 1030
let yhi = ylo + ($ppl$ylen)
let xlo = ($ppl$xorg) + ($ppl$xlen) + .2
let xhi = xlo + .3

fill/set_up/nokey/lev=(1010,1030,2) slp
ppl shakey 1, 1, 0.08, 0, 4, 6, `xlo`, `xhi`, `ymid`, `yhi`
ppl fill

fill/over/set_up/key/lev=(980,1010,5)/pal=black/pat=6patterns slp
ppl shakey 1, 1, 0.08, 0, 4, 6, `xlo`, `xhi`, `ylo`, `ymid`
ppl fill/over

pattern solid
go fland