composites

[Charles Seman]

Teddy,

If any of your data have undefined (missing) values, be careful.  GrADS
ave() function does the averaging correctly, but defining an arithmetic
average without using GrADS built-in functions gives different results
(in essence, if *any* point in the time series at a given spatial point
is undefined, the defined arithmetic average at that point is also
undefined)... I'm also forwarding two emails to you related to this...

I hope this helps,
Chuck

Teddy Allen wrote:
> Dear GrADS users,
> I would like to create a composite image of non-sequential time periods. In my dataset, I would like to composite t=400, t=424, t=532, and t=664 into one contour. I am competent in creating averages with sequential time steps, but am unable to create averages for times that are irregular in pattern.
> I have searched the on-line archives, but did not locate an answer. Does any body have a suggestion? ( I am using GrADS version 1.8SL11 on a PC.)
>
> Thank you,
> Teddy Allen
>
>
> To move quickly, go alone. To move far, go together. --- African Proverb
>
>
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--

Please note that Charles.Seman at noaa.gov should be considered my NOAA
email address, not cjs at gfdl.noaa.gov.

********************************************************************
 Charles Seman                                Charles.Seman at noaa.gov
 U.S. Department of Commerce / NOAA / OAR
 Geophysical Fluid Dynamics Laboratory         voice: (609) 452-6547
 201 Forrestal Road                              fax: (609) 987-5063
 Princeton, NJ  08540-6649            http://www.gfdl.noaa.gov/~cjs/
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