Template problem

[Douglas Clark]

John,

Assuming that your files have 9 or 10 days' of data in each, I think you'll need to use the CHSUB option - see GrADS index
 http://grads.iges.org/grads/gadoc/gadocindex.html
under control file > options > template (or the likes).

With your current template, the way the template works is such that every day's data is assumed to be in a different file - because you have %d2 in the template. So when you set the time to 1997/01/01, GrADS looks for data in a file called 199701_01-01_2D.dat, which doesn't exist - so it says all values are undefined (arguably it might be more useful if GrADS said "can't find file" at this point, but it doesn't).  With time 1997/01/02, GrADS looks for data in a file called 199701_02-02_2D.dat, and so on.

I think CHSUB will come to your rescue (although I have never used it myself). You need a ctl file with something along the lines of
DSET ^199701_%ch_2D.dat
CHSUB   1  9 01-09
CHSUB   10  19 10-19
CHSUB   20 31 20-31
OPTIONS template

The first two integers on each CHSUB line will depend on the time step given in yout TDEF line - I have assumed daily data. See the GrADS documentation for details.

Doug


>>> johnguhin at GMAIL.COM 26/02/2007 07:14 >>>
 Hi,
       I have three files like these....
199701_01-09_2D.ctl
199701_10-19_2D.ctl
199701_20-31_2D.ctl

I wrote a control file like this...
dset ^199701_%d2-%d2_2D.dat
options template
................................................

I can open the control file, but while plotting it says
Cannot contour grid - all undefined values

But I can plot from individual files.  Where am I doing wrong?

--
John Guhin


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