Problem in sst plot

Diane Stokes Diane.Stokes at NOAA.GOV
Wed May 13 23:22:55 EDT 2009


Sorry that didn't fix all cases for you.  It worked for me running grads
v1.9b4 and v2.0.a3 on IBM AIX.

I'm confused by your result with:
  'set lon -180 180'
you only see -180º to 0º.  And with:
  'set lon 180 540'
you only see 0º to 180º.  Do you have those results swapped in the text
of your msg?

If you don't get advice from anyone else, I could only suggest you add a
couple more significant digits (3's in this case) to your increment values.

    Good luck.
       Diane


Fil wrote:
> Hi, Diane
>
> Thanks a lot for your help, your solution works perfectly for polar
> stereographic projections. But on other projections it still doesn't
> show anything from -180º to 0º longitude. If I try to plot just for
> North America, I get an "Entire Grid Undefined" message.
>
> With 'set lon -180 180' it only draws from -180º to 0º. With lon 180 540
> only draws from 0º to 180º. With lon -360 0 it won't draw anything. And
> with 0 360 it will draw the entire globe, but with the problem (for me)
> of getting centered in lon 180º which cuts Europe in half.
>
> Thanks.
>
> 2009/5/13 Diane Stokes <Diane.Stokes at noaa.gov
> <mailto:Diane.Stokes at noaa.gov>>
>
>     Hi, Filipe.
>
>     I recently ran into the same problem with a different dataset on the
>     same grid.
>
>     The spatial resolution the data you are viewing is 1/12 of a degree.
>     The increment in the xdef and ydef statements of your control file is
>     0.083.  (That's how the increment is stored in the grib file, so it's
>     not a result of anything you did wrong).
>
>     That increment value is not sufficient to wrap the data completely
>     around the globe.  You have 4320 points in your xdef:
>      4321 x 0.083 = 358.643
>
>     If you zoom in on the north pole, you'll see the data displayed does not
>     extend far enough north either.
>
>     If you add a few significant digits to the increment values in your xdef
>     and ydef statements, eg:
>
>      xdef 4320 linear 0.042000 0.083333
>      ydef 2160 linear -89.958000 0.083333
>
>     you'll get a more accurate mapping of the data.  The values above will
>     also bring the left and right edge of the grid sufficiently close that
>     GrADS will know that the data does wrap the globe.  You'd then be able
>     to display the field when setting longitude values less than 0 or
>     greater than 360.
>
>       Diane
>
>
>
>     Filipe wrote:
>
>         Hello all,
>
>         I'm trying to plot sst data from
>         ftp://polar.ncep.noaa.gov/pub/sst/ophi/ ,
>         but for some reason I get a white strip at longitude 0º when
>         using nps
>         projection, as you can see from this pic:
>
>         http://img8.imageshack.us/img8/2815/userlist2.png
>
>         When using any other projection, grads only draws from lon > 0º,
>         as you can
>         see from these pics:
>
>         http://img8.imageshack.us/img8/5487/userlist1.png
>         http://img8.imageshack.us/img8/7201/userlist3.png
>
>         I don't know what I'm doing wrong, hope someone can help me. I'm
>         using
>         latest grib2ctl.pl, wgrib v1.8.0.12x and grads 2.05a (I also
>         tested v1.9 and
>         opengrads 2.05). I used the script http://pastebin.com/f3dc65253
>
>         Best regards.
>
>
>
>
> --
> Fil - MeteoPT.com



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