set mode verify    ! display the commands at the user's console
! custom_contour.jnl *sh* 11/91 - added some axis customizations 11/93
!                    *sh* 5/94 - restore default SET GRID on exit

! *acm* 7/01 update /xlimits and /ylimits to /hlimits and /vlimits


! Description: show customizable features of PLOT+ contouring within FERRET

! in case there are left-over regions from previous commands
cancel region

! define an arbitrary function to use as a contouring example
define axis/x=-20:20:1 x2020
define axis/y=-20:20:1 y2020
define grid/x=x2020/y=y2020 g2020
set grid g2020
let circle = (x^2 + y^2) ^ 0.5
let/title="SAMPLE FUNCTION" my_var = circle * exp((10-(i+j))/50)

! produce a default contour plot
contour my_var
message

! change the contour levels - unequally spaced
contour/levels=(1,7,.5)(7,30,3)(11.3) my_var
message

! omit contour labels ("-3")
contour/levels=(1,30,2,-3) my_var
message

! mix: no labels ("-3"), 3 decimal points, and no decimal points ("-1")
contour/levels=(1,5,0.3,-3)(6,15,2,3)(16,30,1,-1) my_var
message

! mix: normal lines, dashed lines and heavy lines
cont/level="(1,30,2,-1) LINE(1,7,2,1) DARK(9,15,2,1) DASH(17,29,2,1)" my_var
message

! mix: three line colors
contour/level="(1,30,1,-1) PEN(5,10,1,2) PEN(11,20,1,3) PEN(21,30,1,4)" my_var 
message

! make contour labels bigger
! note: this feature remains in effect until explicitly removed
ppl conset 0.15
contour/levels="(1,30,3) PEN(1,30,3,1)" my_var
message

! do contour labels in color in Triplex Roman font
! note: this feature remains in effect until explicitly removed
ppl conpre @P2@TR
contour/levels=(1,30,3) my_var
message

! add units of "cm" in Complex Itallic font to the contour labels
! note: this feature remains in effect until explicitly removed
ppl conpst @CIcm
contour/levels=(1,30,3) my_var
message

! give explicit axis bounds and tic interval
contour/levels=(1,30,3)/hlimits=-20:20:10/vlimits=-20:20:10 my_var

! restore normal operation
ppl conpre
ppl conpst
ppl conset 0.08
contour/lev=(1,30,1,-1)/set_up my_var
set grid abstract
set mode/last verify