Re: [ferret_users] Extrapolation on time axis

[Jaison Kurian <jaison@xxxxxxxxxxxxxxxxxx>]

Hi Jerome,
            "@FNR" will work on "axes" rather than on "grid". So basically
you have to use [t=@FNR] instead of [gt=@FNR]. This example works fine for
me.
!-------------------------------------------------------------------------
   define axis/t="18-jul-2006 00:00":"21-jul-2006 00:00"/npoints=4 time
   let V = RANDU(t[gt=time])

   define axis/t="18-jul-2006 00:00":"23-jul-2006 00:00"/npoints=6 timex
   let V1   = V[gt=timex@LIN] ! variable on destination time axis
   let V2   = V1[t=@FNR]      ! fill the missing values at the end

   list V1, V2                
!-------------------------------------------------------------------------

Follow this example. Let me know if you have any questions.

Regards,

Jaison 

On Mon, 24 Jul 2006, Jerome Fiechter wrote:

> Hello ferreters,
> 
> I am trying to extrapolate a variable on the time axis using the @FNR 
> function, but it does not seem to work.
> 
> I have a variable V defined on a time axis TIME1 (t="18-jul-2006 
> 00:00":"21-jul-2006 00:00"/npoints=4), which I want to interpolate on a 
> time axis TIME2 (t="18-jul-2006 00:00":"23-jul-2006 00:00"/npoints=6). 
> My approach was the following:
> V1 = V[gt=TIME2@LIN]
> V2 = V1[gt=TIME2@FNR]
> but V2 ends on 21-jul-2006 and the missing values for 22- and 
> 23-jul-2006 are not filled out by the @FNR function.
> 
> Any suggestions would be greatly appreciated. Thank you!
> 
> Jerome
>