Re: [ferret_users] Problems with curv_to_rect

[Stephen Guimond <sguimond@xxxxxxx>]

Hi Jean,

The problem may lie in your "radius of influence".  You used 0.2 degrees.  I would try something larger to start.  I have gotten this error before and this was the solution.  Also, check to make sure your longitudes are on the same scale (i.e. 0 to 360 rather than -180 to 180).

Steve

----- Original Message -----
From: jean oliveira <jeanbrazil@xxxxxxxxxxx>
Date: Thursday, December 25, 2008 8:49 pm
Subject: [ferret_users] Problems with curv_to_rect
To: ferret user 2 frret user 2 <oar.pmel.ferret_users@xxxxxxxx>

> 
> Dear Ferreters,
> I’m trying to work with global hycom data from coaps.fsu.edu. The 
> data are available in curvilinear coordinate, but I want to work in 
> rectilinear latitude-longitude grid. I tried the following:
> 
> 
>        NOAA/PMEL TMAP
>        FERRET v6.1
>        Linux(g77) 2.6.9-22. - 03/26/08
>        
> 
> yes? use "http://hycom.coaps.fsu.edu:8080/thredds/dodsC/glb_analysis";
> yes? sho dat
>     currently SET data sets:
>    1> http://hycom.coaps.fsu.edu:8080/thredds/dodsC/glb_analysis  
> (default) name     title                                            
>       I                 J               K           L
> LATITUDE                                                 1:4500    
> 1:3298    ...       ...
> LONGITUDE                                              1:4500    
> 1:3298    ...       ...
> SSH sea surf. height  [60.5H]                        1:4500    
> 1:3298    ...             1:1859
> 
> yes? let lonin = longitude[d=1, i=2800:3220 , j=958:1390] yes? let 
> latin = latitude[d=1, i=2800:3220 , j=958:1390]
> yes? ! ! (“i” and “j” are defining an area a little bit bigger than 
> the area defined by axis below)  
> yes? ! Define output grid and a variable on the output grid  
> yes? define axis/x=60w:29W:0.08/modulo/units=degrees xaxyes? def 
> axis/y=40S:10S:0.08/units=degrees yaxyes? let lonlatout = y[gy=yax] 
> + x[gx=xax]  
> yes? ! Compute the mapping to the rectangular grid, save to a 
> fileyes? let map = curv_to_rect_map ( 
> lonin,latin,lonlatout,0.2)yes? save/clobber/file=curv_map.nc  map  
> yes? ! Apply the mapping to the data fields  
> yes? cancel var/allyes? use curv_map.ncyes? let out_ssh = 
> curv_to_rect(ssh[d=1,L=1], map[d=2])
> yes? Save/file=out_ssh.nc   out_ssh  
> yes? exit
> 
> NOAA/PMEL TMAP
>        FERRET v6.1
>        Linux(g77) 2.6.9-22. - 03/26/08
>        
> yes? use out_ssh.nc   
> yes? shade out_ssh
> 
> But when I try to make a “ shade  out_ssh” ferret gives me “ NO 
> VALID DATA”. What is it wrong?. Could anyone help me?
> 
> Thanks
> 
> Jean
> _________________________________________________________________
> Mais do que emails! Confira tudo o que Windows Live™ pode oferecer.
> http://www.microsoft.com/windows/windowslive/
> 
> 

=======================================================
Stephen R. Guimond
Graduate Research Assistant
Florida State University
Center for Ocean-Atmospheric Prediction Studies (COAPS)
=======================================================