[ncl-talk] QUESTIONS OF DRAWING WINDBARB WITH SCATTER STATIONS

[Mary Haley]

You are trying to take 1-dimensional random data and treat it as a 2D
rectilinear grid, which assumes that you have the same latitudes across
each longitude dimension, and the same longitudes across each latitude
dimension.

This is not going to work, because your data is not rectilinear.

Unfortunately, the gsn_csm_vector_xxxxx functions don't currently allow you
to draw vectors at random points.

We have a special function called wmvectmap that do what you want:

http://www.ncl.ucar.edu/Document/Functions/Built-in/wmvectmap.shtml

See example weather_sym_9.ncl at:

http://www.ncl.ucar.edu/Applications/weather_sym.shtml

--Mary




On Tue, Jun 20, 2017 at 6:55 PM, Zhu CE <lovingzhuce at 163.com> wrote:

> Hi everyone,
>
> I want to draw observed winds from scatter stations in windbarb.
>
> I used *onedtond* function to convert wind data from 1-D to 2-Ds, and
> assign latitude and longitude to the new 2-Ds wind data's coordinate.
>
> Finally, I used *gsn_csm_vector(wks,uWND,vWND,resV) *to draw windbarbs.
>
> NCL tells me that "*warning:VectorFieldSetValues: irregular coordinate
> array vfXArray non-monotonic: defaulting vfXArray*", "*warning:VectorFieldSetValues:
> irregular coordinate array vfYArray non-monotonic: defaulting vfYArray*",
> and I got a wrong plot.
>
> Attachments are my NCL script, the data, the wrong plot and the right plot
> I want.
>
> Any mistakes I had done? Could you help me? Thanks!
>
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