Autoscaled TS-diagram

[nrix@xxxxxxxxxxxxxxxxxxxx]

Steve asked me to send around a journal file to produce 
a ts-plot with density contours underlayed.
Here's a version that uses autoscaling and colour symbols over 
sigma contours.

\cancel mode verify
! communicate the T and S data ranges to PLOT+
plot/vs/set_up/k=1 salt,temp

! set axis limits for salt 
ppl %range ($ppl$xmin1) ($ppl$xmax1) 50
define axis/x=($ppl$range_low):($ppl$range_high):($ppl$range_inc)/Units="psu" xsalt

!set  axis limits for temp
ppl %range ($ppl$ymin1) ($ppl$ymax1) 50
define axis/y=($ppl$range_low):($ppl$range_high):($ppl$range_inc)/units="centigrade" ytemp

! create the base contour plot
define grid/x=xsalt/y=ytemp gts
contour/set_up rho_un(x[g=gts],y[g=gts],0)-1000.
go unlabel 1
go unlabel 2
go unlabel 3
ppl xlab "Salinity (psu)"
ppl ylab "Potential Temperature (deg C)"
ppl title  
ppl contour

! overlay the T-S data
plot/vs/set_up/k=1/overlay/nolabel salt,temp
ppl color 1 0 0 100     ! change pen 1 to colour blue -> col.symbols
ppl pen 1,1
ppl plot/over 

! reset pen to black
ppl color 1 0 0 0     ! change pen 1 to rgb_colour 0 0 0
ppl pen 1,1

set mode/last verify

Cheers 
     Nils


address:
---------------------------------------------------------------------------
Nils H. Rix
Dept. Theor. Oceanogr.            phone: (nat.)     0-431-597-3986
Inst. f. Meereskunde                   : (int.)  ++49-431-597-3986
Duesternbrookerweg 20               fax:         ++49-431-565-876
24105 Kiel, FRG                   e-mail: nrix@ifm.uni-kiel.de 
---------------------------------------------------------------------------