[gradsusr] how to reveres latitudes in nc file

[Lee Byerle]

Kishore,
 
Below may also be helpful.  It is sample fortran code that can reverse the latitude indices, and writes back to binary (assuming .nc is first dumped to binary):
.
.
.
irec1=1
irec2=1
 
do nvar=1,5   !Variables in binary file, with u-wind
if(nvar.eq.1) then    
  do k=1,nk
    read(1,rec=irec1)vgrads  !read data in .nc file
    do i=1,ni
       do j=1,nj
           u(i,j,k)=vgrads(i,nj+1-j)               !reverse j-index
         enddo
      enddo
      irec1=irec1 + 1
     enddo
 
c now write to file w/latitude (j-index) reversed:
 
do k=1,nk
 do i=1,ni
   do j=1,nj
     var(i,j) = u(i,j,k)
    enddo
   enddo
   write(17,rec=irec2)var
   irec2=irec2 + 1
enddo
.
.
etc.
 
The new binary output, with latitude starting at +90, can be viewed with a .ctl file using options yrev.
 
Lee

From: Charles Seman - NOAA Federal <charles.seman at noaa.gov>
To: GrADS Users Forum <gradsusr at gradsusr.org> 
Sent: Tuesday, March 26, 2013 1:09 PM
Subject: Re: [gradsusr] how to reveres latitudes in nc file

Kishore,

Have you tried the "yrev" option? 
http://grads.iges.org/grads/gadoc/descriptorfile.html#OPTIONS

You would make a GrADS data descriptor file to open the .nc file, and 
include in the data descriptor file the line:
options yrev

Hope this helps,
Chuck

On 03/26/2013 01:40 AM, Kishore Babu wrote:
> Dear grads users,
>
> My nc file has latitudes as below
>
> latitude = -90, -87.5, -85, -82.5, -80, -77.5, -75, -72.5, -70, -67.5, -65,
>      -62.5, -60, -57.5, -55, -52.5, -50, -47.5, -45, -42.5, -40, -37.5,
> -35,
>      -32.5, -30, -27.5, -25, -22.5, -20, -17.5, -15, -12.5, -10, -7.5, -5,
>      -2.5, 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30,
> 32.5,
>      35, 37.5, 40, 42.5, 45, 47.5, 50, 52.5, 55, 57.5, 60, 62.5, 65,
> 67.5, 70,
>      72.5, 75, 77.5, 80, 82.5, 85, 87.5, 90 ;
>
> But, I need to have latitudes in reveres such as below...
>
> latitude = 90, 87.5, 85, 82.5, 80, 77.5, 75, 72.5, 70, 67.5, 65, 62.5, 60,
>      57.5, 55, 52.5, 50, 47.5, 45, 42.5, 40, 37.5, 35, 32.5, 30, 27.5, 25,
>      22.5, 20, 17.5, 15, 12.5, 10, 7.5, 5, 2.5, 0, -2.5, -5, -7.5, -10,
> -12.5,
>      -15, -17.5, -20, -22.5, -25, -27.5, -30, -32.5, -35, -37.5, -40,
> -42.5,
>      -45, -47.5, -50, -52.5, -55, -57.5, -60, -62.5, -65, -67.5, -70,
> -72.5,
>      -75, -77.5, -80, -82.5, -85, -87.5, -90 ;
>
> Could you please anybody let me know how it is changed?
>
> Thank you in advance..
>
> Regards,
>
> Kishore
>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>

-- 

Please note that Charles.Seman at noaa.gov should be considered my NOAA
email address, not cjs at gfdl.noaa.gov.

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  201 Forrestal Road                              fax: (609) 987-5063
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