Hi Prasad,
Your commands for plotting the polygons look fine. What version of
Ferret are you using?? I just did an example and was able to use over
500,000 polygons. Starting with Ferret v5.53, Ferret uses dynamic
memory allocation for polygon coordinates and so in theory an unlimited
number of polygons can be plotted with one POLYGON command. Perhaps
because of system resources available on your machine, Ferret is not
able to allocate all the memory it needs to plot them all at once. You
can probably do the polygon plot in several steps; something like this
(and you may need to increase memory available with SET MEMORY/SIZE= )
plot/vs/hlim=50:70/vlim=0:10 LONGITUDES,latitudes
LET npts = `longitudes,return=isize`
go polymark polygon/hlim=50:70/vlim=0-10N/ov/i=1:50000 longitudes
latitudes sla square
go polymark polygon/hlim=50:70/vlim=0-10N/ov/i=50001:100000 longitudes
latitudes sla square
go polymark polygon/hlim=50:70/vlim=0-10N/ov/i=100001:150000 longitudes
latitudes sla square
go polymark polygon/hlim=50:70/vlim=0-10N/ov/i=1:150001: `isize`
latitudes sla square
Ansley
Prasad Thoppil wrote:
In
case if you missed this posting --
Hi
I have downloaded along-track sea level anomalies from
ftp://ftp.cls.fr/pub/oceano/AVISO/SSH/duacs/global/nrt/sla/en/
The data file looks something like this:
currently SET data sets:
res_oer_en_20346_20364.nc (default)
name title I J
K L
DELTAT Time gap between two measuremen ... ... ...
...
NBPOINTS Number of measurements for each ... ... ...
1:472
CYCLES Cycle numbers for each pass 1:1 ... ...
1:472
LONGITUDES
Longitude of each measurement 1:185877 ... ...
...
LATITUDES
Latitude of each measurement 1:185877 ... ...
...
BEGINDATES
Date of first measurement for e 1:1 ... ...
1:472
DATAINDEXES
Data index in theoretical pass 1:185877 ... ...
...
SLA Sea Level Anomaly 1:1 1:185877 ...
...
I want to plot SLA over a small region say 50E-70E, 0-10N using go
polymark script. Here is what I used
plot/vs/hlim=50:70/vlim=0:10 LONGITUDES,latitudes
go polymark polygon/hlim=50:70/vlim=0-10N/ov longitudes latitudes sla
square
then it gives me " Too much polygon data to plot at once"
No plot is generated. I use v5.8 Linux(g77) ferret version.
Any help would be appreciated.
Thanks,
Prasad
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