[gradsusr] xdfopen cdf file dimension problem/question

Thomas W. Collow tcollow at eden.rutgers.edu
Thu Aug 26 15:56:20 EDT 2010


Hello, I am having an issue with displaying a .cdf file using GrADS.  To keep it simple I will refer to the file as ?file.cdf.? The file is a time series of soil water content at different depths.  The header of the file contains only two dimensions, depth and time.  I want to read this file using GrADS.  

This is what happens when I use sdfopen:
ga->sdfopen  file.cdf
Scanning self-describing file file.cdf
SDF file has no discernable X coordinate.

My next approach is to use xdfopen and create a control file using information in the header and to specify the latitude and longitude.   Here is my control file, call it ?control?

DSET file.cdf
TITLE Data
UNDEF -9999
XDEF lon 01 levels -98 
YDEF lat 01 levels 35 
TDEF time 24 18:07Z31jul2010 1hr
ZDEF depth 8 levels 5 15 25 35 60 85 125 175
VARS 2
watcont_W=>smw 8 99 water content west
watcont_E=>sme 8 99 water content east
ENDVARS

Now I do xdfopen control and get this error
ga-> xdfopen control
Scanning Descriptor File:  control
Alleged lon dimension (from YDEF) is not an SDF dimension.  Cannot continue.
Lon dimension name is:
lat
.
Alleged lat dimension (from XDEF) is not an SDF dimension.  Cannot continue.
Lat dimension name is:
lon
.
SDF file file.cdf was not successfully opened & parsed.

I am trying to specify a specific latitude and longitude since I know what it is.  It is just not a dimension in the cdf file header.  Any suggestions on how I can fix this problem or is this file not able to be read by GrADS?

Thanks
Tom



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