[gradsusr] plot the average wind vector

[Jeffrey Duda]

Yi-Chih,
The two things I would try are:
1) Instead of displaying the areal average using "d aave...", try defining
the variable as the output of aave like this:
"define uave = aave(u, x=65, x=93, y=37, y=65)"
"define vave = aave(v, x=65, x=93, y=37, y=65)"
"set gxout vector"
"d uave;vave"

2) If (1) doesn't work, use the set
defval<http://www.iges.org/grads/gadoc/gradcomdsetdefval.html>command
to individually set the value of the component fields by using the
two aave commands, one for each component.  That is, try something like:
ii = 65
jj = 37
ii_max = 93
jj_max = 65
'd aave(u, x=65, x=93, y=37, y=65)'
u_value = subwrd(result,4)
'd aave(v, x=65, x=93, y=37, y=65)'
v_value = subwrd(result,4)
while (ii <= ii_max)
   while (jj <= jj_max)
      'set defval uave 'ii' 'jj' 'u_value
      'set defval vave 'ii' 'jj' v_value
      jj = jj + 1
   endwhile
   ii = ii + 1
endwhile

'd uave;vave'

Jeff Duda

On Tue, Nov 8, 2011 at 10:50 AM, Yi-Chih Huang <dscpln at gmail.com> wrote:

> Hello,
>
>     I am trying to plot the average wind vector over a horizontal range.
> But I can't get an arrow, but only a value at most as below.  Could anyone
> tell me the right commands to show the average wind vector over a
> horizontal range?
>
> ga-> d aave(u, x=65, x=93, y=37, y=65);aave(v, x=65, x=93, y=37, y=65)
> Result value = -3.55342
> ga-> d amean(u, x=65, x=93, y=37, y=65);amean(v, x=65, x=93, y=37, y=65)
> Result value = -3.56684
> ga-> d ave(u, x=65, x=93, y=37, y=65);ave(v, x=65, x=93, y=37, y=65)
> Error from AVE: Invalid option flags
> Operation Error:  Error from ave function
>   Error ocurred at column 1
> DISPLAY error:  Invalid expression
>   Expression = ave(u,x=65,x=93,y=37,y=65)
>
>     Thanks much,
>
>                    Yi-Chih
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>


-- 
Jeff Duda
Iowa State University
Meteorology Graduate Student
www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20111109/2da28e5d/attachment-0003.html