I need to write some text on a Hammer projection,
and didn't find an ad hoc tool in the Ferret projection scripts.
I wrote this mp_annotate.jnl script which works well
for my needs. I hope it is versatile enough for other usages. I
would appreciate if you could test it, so I can propose a more
robust and versatile version.
\ cancel mode verify
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++!
! mp_annotate.jnl -- Map projection version of
annotate command. For
! working with map projection
scripts in Ferret v7
!
! Olivier Marti
! 07/2019
! Description: write text on a predefined map
projection.
!
! This script presumes that following are
predefined a projection script
! run previous to this script:
!
! x_page field
describing transformation from lat/lon to X page coordinates
! x_page field
describing transformation from lat/lon to Y page coordinates
! mp_mask
mask for the map projection
!
! Usage: $1 $2 $3 $4
! Yes? GO mp_annotate xpos ypos text
[annotate_qualifiers]
! $1 - X coordinates of text (longitude)
! $2 - X coordinates of text (latitude)
! $3 - Texte
! $4 - The annotate qualifiers (eg.
halign/valign/angle/size)
!
! Example:
! set win/size=.4
! use coads_climatology
! set region/x=130:250/y=20:64/l=1
! go mp_hammer
! let
mp_standard_parallel=mp_standard_paralell !(Strange bug in
mp_hammer)
! set grid sst
! shade/noaxis sst, x_page, y_page
! go mp_land
!
! use polydata
! go mp_polymark poly/over/noaxis/key lon lat
sst star 0.5
! go mp_annotate 180 40 "SST"
/halign=0/valign=0/size=0.3
!
! Notes:
! Mostly based on mp_polymark by Jonathan
Callahan (Thanks !)
!
! Argument check
query/ignore $1"<usage: yes? GO mp_annotate
xpos ypos text [annotate_qualifiers]"
query/ignore $2"<usage: yes? GO mp_annotate
xpos ypos text [annotate_qualifiers]"
query/ignore $3"<usage: yes? GO mp_annotate
xpos ypos text [annotate_qualifiers]"
define symbol MeQual =
$4"halign=0/valign=0/angle=0"
! Add a leading / to MeQual if needed
IF ($MeQual"false|*>true") THEN
IF `strrindex ( "($MeQual)", "/" ) NE 1` THEN
DEFINE SYMBOL MeQual = /($MeQual)
ENDIF
!message/cont "If this script does not complete
you will need to rerun the map projection script."
!
! Save the region and grid
!
define region/default save
set grid/save
! acm (as in mp_land etc)
! tie down mp_central_meridian and parallel or
else they get redefined
! when we cancel the region and use the one
implied by lon and lat that
! come into this script.
set data/save
set grid/save
let/quiet mp_x = x
let/quiet mp_xmin = `mp_x[i=@min]`
let/quiet mp_xmax = `mp_x[i=@max]`
let/quiet mp_y = y
let/quiet mp_ymin = `mp_y[j=@min]`
let/quiet mp_ymax = `mp_y[j=@max]`
let/quiet mp_std_parallel_north = mp_ymax
let/quiet mp_std_parallel_south = mp_ymin
!
! This test will keep the central meridians
defined by "from space" views
!
let/quiet mp_test = `mp_central_meridian` -
`(mp_x[i=@max] + mp_x[i=@min])/2`
if `mp_test eq 0` then
let/quiet mp_central_meridian = `(mp_x[i=@max]
+ mp_x[i=@min])/2`
endif
let/quiet mp_test = `mp_standard_parallel` -
`(mp_y[j=@max] + mp_y[j=@min])/2`
if `mp_test eq 0` then
let/quiet mp_standard_parallel = `(mp_y[j=@max]
+ mp_y[j=@min])/2`
endif
cancel variable mp_test
! Cancel the region because the I index info is
used to restrict
! the points to be plotted as a line.
!
cancel region/x/y
!
! Alter the map projection equations to use xpos
and ypos
!
let/quiet mp_x = $1
let/quiet mp_y = $2
annonate/user/xpos=`x_page*mp_mask`/ypos=`y_page*mp_mask`($MeQual)
$3
!
! Restore the region, grid and map projection
equations
!
set region save
set grid/restore
let/quiet mp_x = x
let/quiet mp_y = y
let/quiet mp_test = `mp_central_meridian` -
`(mp_x[i=@max] + mp_x[i=@min])/2`
if `mp_test eq 0` then
let/quiet mp_central_meridian = (mp_x[i=@max] +
mp_x[i=@min])/2
endif
let/quiet mp_test = `mp_standard_parallel` -
`(mp_y[j=@max] + mp_y[j=@min])/2`
if `mp_test eq 0` then
let/quiet mp_standard_parallel = (mp_y[j=@max]
+ mp_y[j=@min])/2
endif
cancel variable mp_test
let/quiet mp_std_parallel_north = mp_y[j=@max]
let/quiet mp_std_parallel_south = mp_y[j=@min]
let/quiet mp_lambda = mp_x * deg2rad
let/quiet mp_phi = mp_y * deg2rad
!++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++!
set mode/last verify
