RE: [ncl-talk] coordinate subscripting

From: Adam Phillips (asphilli AT cgd.ucar.edu)
Date: Wed Dec 01 2004 - 09:54:37 MST

  • Next message: Mail System Internal Data: "DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA"

    >Dear Sylvia,
    >
    >The domain I want in my data is from 40West to 20East, which correspond to
    >points from :
    >320 to 360
    >and
    >360 (i.e 0) to 20
    >The problem is that my data longitude is not monotonic. So I can't just
    >extract the domain I want. I suppose I could extract both arrays
    >y1 = x({320:360},{minLat:maxLat}) and
    >y2 = x({0:20},{minLat:maxLat}) and then concatenate y1 and y2 into a
    >variable y. Only thing is that I am not sure how to concatenate y1 and y2.
    >
    >Regards, Marjolaine.

    Marjolaine,

    There is a function in contributed.ncl called lonFlip, which will flip your
    longitudes from 0->360 to -180:180, I think this would be the easiest thing for
    you to do.

    newX = lonFlip(x)
    printVarSummary(newX)
    finalX = newX({-40.:20.},{minLat:maxLat})
    printVarSummary(finalX)

    Make sure you load contributed.ncl before you use lonFlip...

    Adam

    >
    >-----Original Message-----
    >From: Sylvia Murphy [mailto:murphys@cgd.ucar.edu]
    >Sent: Monday, November 29, 2004 6:03 PM
    >To: Marjolaine Rouault
    >Cc: ncl-talk@ucar.edu
    >Subject: Re: coordinate subscripting
    >
    >
    >M,
    >
    >you certainly can use coordinate subscripting. This method is dependent
    >upon what your coordinates look like. if your coordinates go from -180 to
    >+180 then you need to use those values while coordinate subscripting. if,
    >as in your case, they go from 0 to 360 you need to use those values.
    >
    >for example
    >
    >y = x({-20:20},{270:360})
    >
    >in your case you need to mentally convert the region you want into
    >360-mode and then subscript.
    >
    >sylvia
    >
    >
    >
    >On Mon, 29 Nov 2004, Marjolaine Rouault wrote:
    >
    >> Hi,
    >>
    >> I am reading some data which longitude is not "ordered" in the usual way.
    >>
    >> Longitude points from 0 east to 180 east have a longitude which increases
    >from 0 to 180.
    >> Longitude points from 180 west to 0 west have a longitude value which
    >increases from 181 to 360.
    >>
    >> I am trying to extract a domain between 40West and 20 East.Is it possible
    >to do it with coordinate subscripting? What would you suggest is the best
    >way to extract my domain?
    >>
    >> Many thanks, Marjolaine.
    >>
    >>
    >>
    >> _______________________________________________
    >> ncl-talk mailing list
    >> ncl-talk@ucar.edu
    >> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
    >>
    >
    >
    >
    >******************************************************
    >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/
    >******************************************************
    >
    >
    >
    >_______________________________________________
    >ncl-talk mailing list
    >ncl-talk@ucar.edu
    >http://mailman.ucar.edu/mailman/listinfo/ncl-talk

    -------------------------------------------------------------
    Adam Phillips email: asphilli@ucar.edu
    Climate and Global Dynamics Division tel: (303) 497-1726
    National Center for Atmospheric Research fax: (303) 497-1333
    P.O. Box 3000
    Boulder, CO 80307-3000 http://www.cgd.ucar.edu/~asphilli

    _______________________________________________
    ncl-talk mailing list
    ncl-talk@ucar.edu
    http://mailman.ucar.edu/mailman/listinfo/ncl-talk



    This archive was generated by hypermail 2b29 : Wed Dec 01 2004 - 10:17:25 MST