Ferret "how to": adjusting plot margins

[hankin@xxxxxxxxxxxxxxxxxxx (Steve Hankin)]

	Ferret "how to": adjusting plot margins

The script below was contributed by Sim Larkin, who developed it in
conjunction with laying out viewports for publication-ready graphics.
It allows you to precisely and simply control how to fit your plots into
viewports.  For a more detailed understanding try the example given
within the script.


	cheers - steve


                |  NOAA/PMEL               |  ph. (206) 526-6080  
Steve Hankin    |  7600 Sand Point Way NE  |  FAX (206) 526-6744
                |  Seattle, WA 98115-0070  |  hankin@pmel.noaa.gov

===============================================================

\ cancel mode verify
! margins.jnl (10/30/95) (NKL)

! Description: specify plot margins (layout of plot axes to window edges)

! usage:             1       2       3      4
!       GO margins [top] [bottom] [left] [right]
!
!       Arguments not specified will not be modified from current settings.
!       Margins are specified in "inches" from edge of viewport.
!
! defaults          1.4     1.4     1.2    1.0
!
! also
!       GO margins  "reset"     -- RESETS to default plot margins
!       GO margins              -- query the current plot margins
!
! example:
!       yes? go margins 0.2 0.6 " " 1.0
!                                           
!  	set margins to 0.2 on top, 0.6 bottom, left is unchanged, 1.0 on right
!
! a sample session - lay out two frames vertically:
!	yes? SET DATA coads_climatology	! demo data set
!	yes? SET VIEW upper		! use upper half of plot frame
!	yes? SHADE/NOLAB sst[l=1]	! default plot layout
!	yes? GO margins			! look at the current margins
!	yes? GO margins 0.2 0.75	! adjust the vertical margins
!	yes? SHADE/NOLAB sst[l=1]	! look at the resulting plot
!	yes? GO margins  " ",,0.9,0.8	! adjust the horizontal margins
!	yes? SHADE/NOLAB sst[l=1]	! look at the resulting plot
!	yes? GO margins			! ask to look at the new margins
!	yes? SET VIEW lower		! use lower half of plot frame
!	yes? GO margins 0.2 0.75 0.9 0.8! use the same modified margins
!	yes? SHADE/NOLAB sst[l=6]	! make the lower plot
!	yes? GO margins   RESET		! return to default settings

! Note 1: Issue "GO margins ..." AFTER changing the viewport with SET VIEWPORT
!	  because SET VIEWPORT recomputes the origin and axis lengths.
! Note 2: The "PLOT" command recomputes the vertical origin and axis length in
!	  order to accomodate label keys. When adjusting margins for the
!	  PLOT command follow the sequence:
!	  	"PLOT/SET_UP ..." , then "GO margins ..." , then "PPL PLOT"

! -----------make sure ppl is up and running
ppl set junk            1
ppl delete junk 

! -----------prepare to process a query (if no arguments were given)
define alias cmd0 "query/ignore"
define alias cmd1 "message/continue"
define symbol do_query cmd`$1"1|*>0"*$2"1|*>0"*$3"1|*>0"*$4"1|*>0"`  ! 1 or 0

! -----------set symbols - default to current conditions
define symbol top    $1"($vp_height) - ($ppl$yorg) - ($ppl$ylen)|reset>-10|*|"
define symbol bottom $2"($ppl$yorg)"
define symbol left   $3"($ppl$xorg)"
define symbol right  $4"($vp_width) - ($ppl$xorg) - ($ppl$xlen)"

! -----------Old conditions
($do_query) "                            T     B     L    R"
($do_query) "margins are  -- GO margins `($vp_height) - ($ppl$yorg) - ($ppl$ylen)`   `($ppl$yorg)`   `($ppl$xorg)`   `($vp_width) - ($ppl$xorg) - ($ppl$xlen)`"

! ----------Reset is top = -10
define symbol bottom    `if (($top)) le (-10) then 1.4 else (($bottom))`
define symbol left      `if (($top)) le (-10) then 1.2 else (($left))`
define symbol right     `if (($top)) le (-10) then 1.0 else (($right))`
define symbol top       `if (($top)) le (-10) then 1.4 else (($top))`

! -----------change origin, axis length
ppl origin ($left),($bottom)
ppl axlen `($vp_width) - ($left) - ($right)`,`($vp_height) - ($bottom) - ($top)`

! clean up
cancel alias cmd0
cancel alias cmd1
cancel symbol do_query
cancel symbol top
cancel symbol bottom
cancel symbol left
cancel symbol right
set mode/last verify