Plotting gridded binary data

[Eric L. Altshuler]

Brad,

A few questions come to mind.

1. How did you write your data file? Is it written "direct access" or
stream binary with no record control words, or did you write it as
"sequential" in a fortran program? If it is sequential, you need to add
a line in the ctl file:

options sequential

This tells grads that the file contains control words to separate the
records.

2. Does your data file have a header at the beginning and/or between
records? If so, you need to use the 'fileheader' and/or 'xyheader'
keywords in the ctl file (see grads documentation for more info). If
there are headers but grads is not aware of them, the data will look
very strange.

3. Are you sure the starting longitude is 1 degree E, or is it 0 degree E?
If the (1,1) element of the data array has a lon/lat of 0/-90, then your
xdef statement should be:

xdef 360 linear 0 1

Hope this helps.

Best regards,
Eric L. Altshuler
Assistant Research Scientist
Center for Ocean-Land-Atmosphere Studies
Calverton, MD, USA
ela at cola.iges.org