\cancel mode verify
! objective.jnl  11/93 *sh*
! Description: 2D objective analysis of scattered data

! NOTE: See external functions scatter2grid* for options on gridding data

! usage:
!  GO objective xpts ypts zpts "xlo:xhi:xdel" "ylo:yhi:ydel" [cay] [nrng]
!							[filename] [append]
! where
!1-3	xpts ypts zpts 	- 3 arrays representing (X,Y,value) triples
!4	xlo:xhi:xdel 	- output axis specification for first coordinate
!5	ylo:yhi:ydel 	- output axis specification for second coordinate
!6 optional	cay	- interpolation scheme (see PLOT+ CONSET command)
! 			  0.0->Laplacian; large cay->Spline [default=5.0]
!7 optional	nrng	- include points within nrng output grid cells in the
!			  interpolation (see PLOT+ CONSET command) [dflt=5]
!8 optional	filename- file name to receive output [dflt=fer_objective.unf]
!9 optional	append	- "append" to old or create "new" file [default="new"]

! example: Put scattered (long, lat, sst) triples (in variables lons,lats,ssts)
!	   onto a grid that is 1x1 degree on 160E:160W and 20S:20N with
!	   interpolations based on points within 8 grid points (degrees) and
!	   output into file sst_grid.unf
!
!   yes? GO objective lons lats ssts "160:200:1" "-20:20:1" " " 8 sst_grid.unf
 
! check that 5 mandatory arguments are provided and that arg 9 is valid
query/ignore $5%<Use: GO objective xp yp zp "xlo:hi:dx" "ylo:hi:dy" [cay] [nrng] [ofile] ["append"]%
query/ignore $9%new|new|append|delete|<specify "new" or "append" for argument 9%

! remove (spawn rm) old file unless "append" is specified
$9"sp rm -f|new>sp rm -f|append>sp touch|delete>sp rm -f" $8"fer_objective.unf"

! if this output file is already in use via SET DATA then cancel it
CANCEL DATA/NOERROR $8"fer_objective.unf"

! define a grid as per the desired output
define axis/x=$4 obj_xax
define axis/y=$5 obj_yax
define grid/x=obj_xax/y=obj_yax obj_grid

! a message to the user ...
say Your result will be variable "gridded" in data set $8"fer_objective.unf".

! perform the objective alanysis
USER/COMMAND=OBJECTIVE/opt1=$4,$5,$6"5.0",$7"5"/file=$8"fer_objective.unf" $1,$2,$3

! prepare to use the new variable "gridded"
set data/save
file/grid=obj_grid/format=unf/variable=gridded $8"fer_objective.unf"
set variable/bad=1E35 gridded
set data/restore
say Now you can SET REGION and issue:
say ...... >>>  SHADE gridded[d=$8"fer_objective.unf"]  <<<

set mode/last verify