Re: mask the data for a region

> I want to do a EOF analysis for the data at the conterminous US only, so I
> have to mask the data for that region, and data outside of that region should
> be set to missing values. I see some examples to plot:
> http://www.ncl.ucar.edu/Applications/polyg.shtml, but this doesn't mask the
> data. Any ideas or US mask data available?
> _______________________________________________
>

To my knowledge, there is no "US only" mask.

You could get close by use of:
  http://www.ncl.ucar.edu/Document/Functions/Shea_util/landsea_mask.shtml

Assuming you have a global grid:

[1] Mask all ocean/island/.. Keep only land over major continents
[2] Set all grid pts north of 50N; south of 23N;
    west of 130W and east of 65W to _Fillvalue

The alternative if to make a 2D array of (say) 0 and 1
where 1s are over the US. Then use the "mask" function.

Good luck
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Received on Fri Nov 17 2006 - 23:06:24 MST