Re: [ferret_users] Overlaying location of minimum U wind

["William S. Kessler" <william.s.kessler@xxxxxxxx>]

I think y=@loc will do this for you. Look in the documentation for @LOC.

BK

On 04 Feb 2011, at 3:23 AM, Samrat Rao wrote:

> Hi,
>
> I am trying to locate and plot the minimum U wind values on a lat- 
> lon figure. I am attaching the figure generated.
>
> After ploting the U wind contours i use the following:
>
>  repeat/range=0:120:2/name=xpos (  \
>    let minval =  uwnd[x=`xpos`e,y=@min,z=`zl`:`zu`@ave,l=7]; \
>    let ypos = uwnd[x=`xpos`e,y=@loc:`minval`,z=`zl`:`zu`@ave,l=7]; \
>    list ypos; \
>    plot/line=14/color=red/thickness=3/size=0.15/symbol=3/vs/nolabel/ 
> overlay xpos,ypos  )
>
> As you can see the symbols are being plotted below the location of  
> minimum U wind. I have the following questions:
>
> 1) The reason for the incorrect location of the symbols. I am not  
> having this problem with NCEP reanalysis data.
>
> 2) I am unable to get the 'line' qualifier connect the different  
> symbols. How to do this?
>
> 3) At some locations there is a discontinuity (for example around  
> 55E). To me it looks artificial.
>
> 4) In case there is a missing value for 'ypos', then how do i ensure  
> that this does not cause an error and abort in the script execution?
>
> I hope you people will have patience to reduce some of my  
> difficulties.
>
> Thanks,
> Samrat Rao.
> <figures.pdf>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
William S. Kessler
NOAA / Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle WA 98115 USA

william.s.kessler@xxxxxxxx
Tel: 206-526-6221
Fax: 206-526-6744
Web: http://www.pmel.noaa.gov/people/kessler