[GRASS-user] drawing wind vectors

[Hamish]

Alberto Pettazzi wrote:
> <font face="Times New Roman">Hi
> everybody!<br>
> <br>
> I have 2 files, containing u and v component of wind vector
> respectively. Is there any simple way to plot the wind
> field?<br>
> <br>
> thank you as usual,<br>
> </font>
> <div class="moz-signature">-- <br>

[please post in plain text, html makes it hard for some of us to read...]


Use the d.rast.arrow module. See the help page for conversion of u,v to
magnitude,direction. (assuming you can make u,v into raster maps; what
form is the data in?)

d.rast.arrow screenshot here:
  http://grass.osgeo.org/screenshots/raster.php


In Matlab this is known as a quiver plot, here is a addon for Octave to
do that with free software:
  http://octplot.sourceforge.net/quiver.html


I had thought for a while to add to d.rast.arrow wind barb rendering, and
with the advent of GDAL reading the WMO's GRIB format there is a bit more
reason to do that. For now the zyGrib program is nice to look at those:
  http://zygrib.free.fr/


Hamish