[R] How to plot wind direction and strength field

Jenny Barnes jmb at mssl.ucl.ac.uk
Tue Apr 29 14:30:14 CEST 2008


Hi Jim,

I forgot to say that I don't want to create curved arrows, just straight - 
and I would like them to be proportional to the magnitude :o)

Thanks again for your time!

Jenny

On Tue, 29 Apr 2008, Jenny Barnes wrote:

> Hi Jim,
>
> I would like to plot something like figure 2 on this webpage:
> http://www.cnrfc.noaa.gov/storm_summaries/jan1997storms.php
>
> My data is very large - covering the whole globe at 2.5deg resolution so 
> longitude=144 girds, latitude=73 grids and time=32 years - hard to give you 
> that data......Would it help to give you a couple of grid squares worth of 
> data for one year?
>
> Thanks,
>
> Jenny
>
> On Tue, 29 Apr 2008, Jim Lemon wrote:
>
>> Jenny Barnes wrote:
>>> Dear R-help community,
>>> 
>>> I have searched through the archives and not been able ot find any advice 
>>> on how to plot a wind field with one arrow per grid square with the arrow 
>>> pointing in the direction of the wind and it's size proportional to the 
>>> wind strength.
>>> 
>>> I have the wind speed data in arrays of [lon,lat,uwind] and 
>>> [lon,lat,vwind] so it is broken down into u and v components. How do I 
>>> plot it though?!?!
>>> 
>>> Any suggestions very wecome indeed - I seem to have hit a brick wall.....
>> 
>> Hi Jenny,
>> Some time ago, there was a request for a direction field plot. I programmed 
>> a basic function, but perhaps the person found another solution, for I 
>> never heard any more of it. However, this is not too hard to do in R, even 
>> adding the arrows to a geographical plot. Could you post some data and 
>> perhaps a link to an example of what output you would like?
>> 
>> Jim
>> 
>> 
>



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