Re: log10

From: Sylvia Murphy (murphys AT XXXXXX)
Date: Fri Jan 30 2004 - 16:04:01 MST


Hi ben,
you're right, NCL does not have a where function, but it does have
the algerbraic > and < operators. In your case I think this will work if
you
don't mind setting all negative values to zero rather than missing:

x<0

will take all values in x < 0 and set them to 0.

sm

On Fri, 30 Jan 2004, Ben Foster wrote:

>
> Hi ncl-talk:
>
> Here's a simple question. I want to plot log10 of my field, e.g.:
>
> var = a->$vars(n)$(time2plot,:,:,lons2plot(i))
> var = log10(var)
> ...
> plot var
>
> If there are values of var <= 0., I get -INF in those areas of the
> array after the log10 (no error or warning messages). It then hangs
> in the plot call.
>
> I don't think ncl has a "where" function, and I don't want to loop
> w/ conditionals, so what is the best way to take log10 of the field
> and substitute a fill_value where the array is <= 0.? Thanks,
>
> --Ben
>
>
> -----------------------------------------------------------------------
> Ben Foster High Altitude Observatory (HAO)
> foster@ucar.edu phone: 303-497-1595 fax: 303-497-1589
> Nat. Center for Atmos. Res. P.O. Box 3000 Boulder CO 80307 USA
> -----------------------------------------------------------------------
>
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-- 

****************************************************** Sylvia Murphy EML: murphys@ucar.edu NCAR CGD/CSEG PHN: 303-497-1720 1850 Table Mesa Drive FAX: 303-497-1333 Boulder CO 80305

WEB: http://www.cgd.ucar.edu/csm/support/ http://www.cgd.ucar.edu/csm/support/CSM_Graphics/ ******************************************************

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