RE: SAVE in EOF analysis

[antonio rodriguez <arv@xxxxxxx>]

Hi Boyin

I'm doing exactly the same kind of calculations and I'm facing the same
problems (not to say the output of eof_stat). Once you have saved your eof's
as a .cdf file you will see that plotting them is an easier task. I've found
that in order to speed the plotting of the eof's I need to set region to a
smaller one and then reset to the whole region.

Cheers

Antonio Rodriguez

> -----Mensaje original-----
> De: owner-ferret_users@ferret.pmel.noaa.gov
> [mailto:owner-ferret_users@ferret.pmel.noaa.gov]En nombre de Ansley
> Manke
> Enviado el: jueves, 25 de septiembre de 2003 23:28
> Para: byh@crces.org
> CC: ferret_users@ferret.wrc.noaa.gov
> Asunto: Re: SAVE in EOF analysis
>
>
> Hi Boyin,
> The EOF functions do a large matrix inversion and so they
> do take time.  In general the size of the matrix is dimensioned
> (NX*NY) by NT, which can quickly become quite large.
> Saving the result is definitely a good idea, so that you have
> the results to work with.
>
> Ansley Manke
>
> Boyin Huang wrote:
>
> > Hi, ferreters:
> >
> > Is the ferret so slow in doing EOF analysis?
> >
> > Using the demo file for eof analysis:
> >
> > -------------------------------------------------------
> > SET REGION/X=67w:1w/Y=11S:11N
> > USE coads_climatology
> > LET eof_xyfcn = eof_space(sst, 0.5)
> > SAVE/CLOBBER/FILE=sst_clim_eof_space.cdf eof_xyfcn
> >
> > USE sst_clim_eof_space.cdf
> > SET VIEW ul; fill/l=1/TITLE="eof 1" eof_xyfcn; go land
> > -------------------------------------------------------
> >
> > Which works fine to me. Now I wish to have EOF in a
> > larger domain, say 120E-70W and 40S-50N.
> >
> > I replaced set region by
> > SET REGION/X=120e:70w/Y=40S:50N
> > and added
> > SET MEMORY/SIZE=260.(my computer memory is 1.5gb).
> >
> > I found that the ferret runs for ever (how long should
> > I wait for?).
> >
> > I tried to diagnose the problem by typing these
> > command lines interactively line by line, and found
> > the problem is that the program was stuck by SAVE
> > command.
> >
> > I then tried NOT to use the save command, but ferret
> > says that the variable was not found.
> >
> > So, do we have to save EOF first, and the read and
> > plot?
> >
> > How can I do the EOF analysis within a larger space
> > domain and long time series? Say, simulated global SST
> > with 200x100 grids for 1200 month, sst(200,100,1200).
> >
> > =====
> > Boyin Huang
> > The Center for Research on the Changing Earth System (CRCES)
> > 10211 Wincopin Circle, Suite 240
> > Columbia, Maryland 21044
> > Tel. 410-992-5300/819 (O), 410-737-4557(H)
> > Fax. 410-992-5944, Email. byh@crces.org
> > http://byh.crces.org
> >
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>
> --
> Ansley Manke  Pacific Marine Environmental Laboratory  Seattle WA
>
>
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