[gradsusr] Wind Arrow

[Thomas Robinson]

Aloha Olivier,

If you use 'set gxout vector' it will plot wind vector arrows.

If you use
'set gxout vector'
'd u;v;mag(u,v)'
where u and v are your wind components, the arrows will be colored based on
the wind speed.

If it's too dense, you can use skip to plot less arrows
'set gxout vector'
'd u;skip(v,10,10);mag(u,v)'

You can use cbar to see what speeds the colors match up to.

Good luck,
-Tom


On Sun, Oct 19, 2014 at 7:25 AM, Jeff Duda <jeffduda319 at gmail.com> wrote:

> Olivier,
> You'll probably want to use a combination of maskout() and set strmden
> <http://www.iges.org/grads/gadoc/gradcomdsetstrmden.html> to control the
> appearance of the arrowheads on a streamline plot.  The maskout() function
> will plot a set of streamlines in an area corresponding to whatever speed,
> direction, or other threshold you want (sounds like you want to use speed
> as a threshold), and all of the streamlines plotted will correspond to the
> current 'set strmden' settings.  Between each display command you will want
> to re-enter the 'set strmden' command with different settings and use
> different thresholds in the maskout() function.
>
> Jeff Duda
>
> On Sun, Oct 19, 2014 at 5:11 AM, Olivier TRECA <otreca at me.com> wrote:
>
>> Hello,
>>
>> My name is Olivier and I’m from France. I use GrADS to make the maps
>> which describe the weather and the migration of the birds.
>>
>> Could see my map on this site :
>>
>> http://www.chasseurdemigrateurs.com/meteo/view/2014/10/19
>>
>> The wind is important but I don’t have found how to make cute arrows and
>> so I use the streamlines. But I’m not happy.
>>
>> What I want to make is small arrows when the wind is light and big one
>> filled for example in red when the wind is stronger.
>>
>> I think it could be possible drawing a rectangle and a triangle at the
>> right place and with the right size… but I’m not aware with this type of
>> manipulation.
>>
>> If somebody could help me !
>>
>> Many thanks
>>
>> Olivier TRECA
>> otreca at me.com
>>
>>
>>
>>
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>>
>>
>
>
> --
> Jeff Duda
> Graduate research assistant
> University of Oklahoma School of Meteorology
> Center for Analysis and Prediction of Storms
>
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>


-- 
Tom Robinson
Treasurer - Graduate Student Organization
Secretary - Student Athletic Fee Committee
Graduate Student - Department of Atmospheric Science
732-718-2323
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