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20000706: subtraction of fields

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  • Subject: 20000706: subtraction of fields
  • Date: Thu, 27 Jul 2000 12:46:17 -0600
>From: "J. Correia" <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200007062225.e66MPkT29407

>hi, im trying to subtract numerous fields including avor and qvectors...
>for example--->sub(avor(geo)^f00,avor(geo)^f12+2) will not work...but the
>one for height works--->sub(hght^f00,hght^f12+2)....my next guess is to
>create the grids i need...then subtract...is all that necessary or is
>gempak playing with my mind?
>thanks,
>james correia jr
>jimmyc
>


Jimmy,

I cannot duplicate your problem, but it may be specific to the size of your
grids.

Your second example shows the use of 2 hght grids to produce a third grid.

Your first (geo implies geo(hght)) which then uses 2 height grids to
produce the 2 geo grids, the 2 avor grids and finally the sub grid.
Depending on the size of your grids, the ammount of buffer space that
Gempak is using for the heap may be exceeded. To get arround that, you can use 
gddiag to compute the intermediate grids.

Steve Chiswell