Re: good u and v, vector plot empty

Hi Paula,

You can't do triangular mesh transformations with vector data, so maybe this is part of the issue. Try not setting trGridType at all to see what happens.

Otherwise, when there's an issue with data not showing up on a map, it's usually because the lat/lon coordinates haven't been specified, or they've been specified but they are not over the part of the plot you're looking at.

You said the code was working for gsn_csm_contour_map, but not gsn_csm_vector_map, so the first thing I would check is that both u and v that you are passing to gsn_csm_vector_map have the lat2d/lon2d attached. It's not enough to just attach them to u.

Second, of course, is make sure your u/v arrays aren't all missing!

If none of this helps, then it will help if I can see your full script and data.

--Mary

On Jul 18, 2011, at 12:53 PM, Paula Doubrawa Moreira wrote:

> Hi, all -
>
> Can anyone help with vector plots?
>
> I'm trying to plot wind vectors for QuikSCAT ocean wind data but getting empty plots.
>
> The scalar plots look perfect for both U and V but when switching the function from gsn_csm_contour_map to gsn_csm_vector_map I get an empty plot.
>
> The variables U and V look like this and a scalar plot for U is attached. Is the vector problem occurring due to the missing values in the swath gaps?
>
> Variable: v
> Type: float
> Total Size: 1974784 bytes
> 493696 values
> Number of Dimensions: 2
> Dimensions and sizes: [Wind_Vector_Cell_Row | 3248] x [Wind_Vector_Cell | 152]
> Coordinates:
> Number Of Attributes: 11
> valid_range : ( 0, 50 )
> hdf_name : wind_speed_selection
> calibrated_nt : 1
> add_offset_err : 0
> scale_factor_err : 0
> SDS_type : Single
> units : m/s
> long_name : meridional wind selection
> _FillValue : 1e+20
> lon2d : <ARRAY of 493696 elements>
> lat2d : <ARRAY of 493696 elements>
>
> The resources set on my script (both for scalar and vector plots) are:
>
> res = True
>
> res@trGridType = "TriangularMesh"
>
> res@pmLabelBarDisplayMode = "Always"
>
> res@lbOrientation = "Vertical"
>
> res@cnFillMode = "RasterFill"
> res@cnLineLabelsOn = False
> res@cnLinesOn = False
> res@cnFillOn = True
>
> res@gsnAddCyclic = False
> res@gsnSpreadColors = True
> res@gsnMaximize = True
>
> res@mpLimitMode = "Corners"
> res@mpLeftCornerLatF = 59.35619
> res@mpLeftCornerLonF = 171.8014
> res@mpRightCornerLatF = 67.80419
> res@mpRightCornerLonF = -101.7952+360
> res@mpCenterLatF = 90
> res@mpCenterLonF = -180
>
> res@vcRefAnnoOrthogonalPosF = -1.0
> res@vcRefMagnitudeF = 5.0
> res@vcRefLengthF = 0.06
> res@vcGlyphStyle = "CurlyVector"
> res@vcMinDistanceF = 0.017
> res@vcMinFracLengthF = 1.0
>
>
> Any ideas?
>
> Thank you very much!
> Paula
>
> --
> Paula Doubrawa Moreira
> Graduate Student - Research Assistant
> International Arctic Research Center
> University of Alaska Fairbanks
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Received on Mon Jul 18 15:57:08 2011