\cancel mode verify
! split_z.jnl
! 10/95 - based on a script submitted by Joachim Dengg
! Description: make a CONTOUR,SHADE, or FILL plot with a split vertical axis
! producing a "magnified" view of the near-surface waters

! usage:	       $1       $2    $3  $4  $5   $6     $7
!   yes? GO split_z command  qualifs var top mid bottom split
! $1 - the plot command (SHADE,FILL or CONT)  (default, "FILL")
! $2 - qualifiers to the plot command - /LEVELS and /PALETTE (default, none)
! $3 - the variable to be plotted (use quotation marks if it contains commas)
! $4 - the depth at the      top    of the plot (default=0)
! $5 - the depth at the split point of the plot (default=1000)
! $6 - the depth at the    bottom   of the plot (default=5000)
! $7 - the fractio of the page given to the upper viewport (default=0.33)

! example:
!   yes? SET DATA levitus_climatology
!   yes? SET WINDOW/ASPECT=1
!   yes? go split_z FILL "/lev=(0,4,.5)(0,30,2)" "temp[X=160W,Y=45S:45N]" 0 500 4000 0.4
! Note 1: a taller, thinner window looks nicer ...
!         yes? SET WINDOW/ASPECT=1
! Note 2: this procedure will not work in a viewport since it uses viewports

! set default values and check for argument errors
define symbol cmnd $1"FILL"
define symbol quals $2"set_up"
define symbol var  $3"<Usage: GO split_z cmnd quals var top mid bottom split"
define symbol topZ $4"0"
define symbol splitZ $5"1000"
define symbol botZ $6"5000"
define symbol vp_split `1-$7".33"`

! clear the screen
cancel viewports

! define viewports for top and bottom panels
! "/text=..." scales the viewports consistently
define viewport/text=.6/y=($vp_split),1 sp_u   ! upper
define viewport/text=.6/y=0,($vp_split) sp_l   ! lower

! the upper frame with the Y axis coming right to its bottom
set view sp_u
define symbol upper_axlen `($ppl$yorg)+($PPL$YLEN)`
define symbol orig_yorg ($ppl$yorg)
ppl origin ,0
ppl axlen ,($upper_axlen)
(($cmnd)/($quals)/z=($topZ):($botZ)/ylimits=($topZ):($splitZ)/set_up ($var))
ppl title   	! no title under plot
ppl axset 1,0	! no lower axis
ppl xlab	! no X axis label
ppl shakey 0	! no key drawn for upper half
ppl ($cmnd)
ppl origin ,($orig_yorg)	! restore Y origin

! the lower frame with the Y axis coming almost to its top
set view sp_l
define symbol axis_gap 0.15
define symbol lower_axlen `($VP_HEIGHT)-($ppl$yorg)-($axis_gap)`
ppl axlen ,($lower_axlen)
(($cmnd)/($quals)/z=($topZ):($botZ)/ylimits=($splitZ):($botZ)/set_up ($var))
ppl axset 0,1	! no upper axis
ppl ylab	! no Y axis label on this part
ppl labs

! set up the color key
define symbol lower_right_x `($ppl$xorg)+($ppl$xlen)`
define symbol lower_right_y `($ppl$yorg)`
! see "Plot Plus for Ferret Manual" for shakey description
ppl shakey 1,1,.12,,,,`($lower_right_x)+0.3`,`($lower_right_x)+0.9`,`($lower_right_y)`,`($lower_right_y)+($lower_axlen)+($axis_gap)+($upper_axlen)`

! plot the lower half and the key
ppl ($cmnd)

! clean up
ppl axset 1,1
cancel symbol cmnd
cancel symbol quals
cancel symbol var
cancel symbol topZ
cancel symbol splitZ
cancel symbol botZ
cancel symbol vp_split
cancel symbol upper_axlen
cancel symbol orig_yorg
cancel symbol lower_right_x
cancel symbol lower_right_y
cancel symbol axis_gap
cancel symbol lower_axlen
set mode/last verify