[las_users] Using Define Symbol Cause Custom Script to Fail

[John Schattel <john.schattel@xxxxxxxx>]

Hi All,

I am using a custom script, curvi_region_subset.jnl, to plot a 
variable.  I'm trying to mask our the portion of the plot for which 
there is no data.  When I do that I get a title for the plot that 
includes the mask logic "if ( mask eq 1 ) then $1".  So I have created a 
symbol to create a title as follows:

def sym newTitle = `$1,return=title`

The inclusion of this line in the script at the bottom of this e-mail 
causes the LAS to complain about bad illegal limits on the x axis.

Any ideas on what is going wrong?  This strategy worked in another 
script I an using so its failure is somewhat baffling.

Regards,

John

\cancel mode verify

! curvi_region_subset.jnl
! 9/12/05 ACM
! 11/2/05 version to call curv_range rather than curv_to_rect_map

! Description: plot a subset of a variable on a curvilinear grid, using 
the region
! that has been set. Overlay a shade plot of the appropriate land mask
! This script assumes
!  1) The curvilinear data set has been opened
!  2) Any desired region has been set in X, Y, Z, and T
!  3) Variables dat_lon and dat_lat have been defined pointing to the 
curvilinear
!     coordinate variables including their units and title

! usage:                   arg1
!  GO curvi_region_subset  varname

! arguments:
! arg1  variable to shade using dat_lon and dat_lat


! Example:
!   USE "/home/ja8/ansley/hazmat/TGLO-his-05-09-12-00-06.nc"
!   LET/TITLE="`lon,RETURN=title`"/UNITS="`lon,RETURN=units`" dat_lon = lon
!   LET/TITLE="`lat,RETURN=title`"/UNITS="`lat,RETURN=units`" dat_lat = lat
!   SET REGION/X=97W:90W/Y=25N:30N/K=1/T="21-sep-2005:08:00"
!
!   GO curvi_region_subset v

define region/default save

! Make a dummy plot to get the values of the region settings, modulo in x

use etopo120; shade/noax/nolab/nokey/pal=white rose; can data etopo120
let xmin = `($xaxis_min)`
let xmax = `($xaxis_max)`
let ymin = `($yaxis_min)`
let ymax = `($yaxis_max)`

! Save the time index corresponding to the region.
let timeindex = `l[gt=$1]`

! See if a region had indeed been set. If not use the range from the
! lon and lat curvlinear variables.

can region
IF `xmin eq 20` THEN
  IF `xmax eq 380` THEN
     LET xmin = `dat_lon[x=@min,y=@min]`
     LET xmax = `dat_lon[x=@max,y=@max]`
  ENDIF
ENDIF

IF `ymin eq -90` THEN
  IF `ymax eq 90` THEN
     LET ymin = `dat_lat[x=@min,y=@min]`
     LET ymax = `dat_lat[x=@max,y=@max]`
  ENDIF
ENDIF

set region save
can region/t
!
! Define a mapping from the curvilinear data to a rectangle bounded by the
! desired output range.
!
!!  def axis/x=`xmin`:`xmax`/npoints=2/modulo/units=degrees xax
!!  def axis/y=`ymin`:`ymax`/npoints=2/units=degrees yax
!!
!!  let lonlatout = y[gy=yax] + x[gx=xax]
!!
!!  ! Compute weights for the mapping
!!  let map = curv_to_rect_map ( dat_lon, dat_lat, lonlatout, 10)
!!  let map = curv_to_rect_map ( dat_lon, dat_lat, lonlatout, 10)
!!  load map
!!
!!  ! map includes the lon and lat indices from the source grid
!!  ! which correspond to coordinates in the dest grid.
!!
!!  let llon = map[i=1,j=@min,l=2,k=@min]
!!  let llat = map[i=@min,j=1,l=3,k=@min]
!!  let ulon = map[i=2,j=@max,l=2,k=@max]
!!  let ulat = map[i=@max,j=2,l=3,k=@max]
!!


! Call curv_range to get the corresponding I and J range, in variable rr
let rr = curv_range (lon, lat, `xmin`, `xmax`, `ymin`, `ymax`, 0)

let llon = `rr[i=1]`
let ulon = `rr[i=2]`
let llat = `rr[i=3]`
let ulat = `rr[i=4]`

! say "lon index range `llon`:`ulon`"
! say "lat index range `llat`:`ulat`"

set region save
can region/t

def sym newTitle = `$1,return=title`

let masked_var1 = if ( mask eq 1 ) then $1

shade \
 masked_var1[i=`llon`:`ulon`,j=`llat`:`ulat`,L=`timeindex`], \
 dat_lon[i=`llon`:`ulon`,j=`llat`:`ulat`], \
 dat_lat[i=`llon`:`ulon`,j=`llat`:`ulat`]

! SHADE the land mask

can region/x/y
!  SHADE/OVER/NOLAB/LEV=(0,0,1)/PAL=grey \
!    mask[i=`llon`:`ulon`,j=`llat`:`ulat`], \
!    dat_lon[i=`llon`:`ulon`,j=`llat`:`ulat`], \
!    dat_lat[i=`llon`:`ulon`,j=`llat`:`ulat`]

go land red

set region save
set mode/last verify