Re: using 2d coord variables

From: Sylvia Murphy (murphys AT XXXXXX)
Date: Wed Jan 22 2003 - 10:40:04 MST

  • Next message: Sylvia Murphy: "Re: using 2d coord variables"

    you have discovered the major limitaton to 2d lat/lon stuff.

    the 2d lat/lon arrays are not coordinate variables because by netCDF rule
    coordinate variables must be 1D. the lat/lon arrays are "associated" to
    the data using the the x@lat2d=LAT2d syntax.

    because they are not coordinate variables, when you want to zoom in on the
    data, you can not use coordinate subscripting.

    This means that when you zoom in on a map, you can only do this by setting
    the mpMinLatF etc resources and passing the plot template the entire data
    array. Only the map is zoomed in, not the data.

    now say you wanted to plot a subset of the data w/o a map as you do with
    gsn_csm_contour. You still can not use coordinate subscripting to
    indicate that you only want to see a contour plot from -30S to 30N. You
    have to know the index values of those latitudes.

    I suspect that your technique did not work b/c you were trying to treat
    those lat/lon arrays as coordinate variables.

    send me a script and I will take a look


    Sylvia Murphy EML: murphys AT
    NCAR CGD/CAS PHN: 303-497-1720
    3080 Center Green Drive FAX: 303-497-1333
    Boulder CO 80301


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