Re: [ferret_users] Picking the time corresponding to maximum value of a variable from an nc file

[Hein Zelle <hein.zelle@xxxxxxxxxxxxx>]

HI Sandhya,

> yes? list hs[l=1:2919@loc:2.2]                                                           
>              VARIABLE : TIME of 2.2 in HS_CM/100 (HOURS)
>              FILENAME : Hs_timeseries.nc
>              TIME     : 01-JAN-2009 01:27 to 31-DEC-2009 22:27 (location of 2.2)
>           954690.
> 
> yes? list t[gt=hs]

Once you have the index, you can print the time value (or put it in a
variable) with

let mytimestring = `t[gt=hs,l=954690],return=tstart`

You can't use recursive backticks, so I usually do this in a few
steps.  I define a new variable which is zero at the maximum so you
can use a fixed value (0.0) for @loc.

let zero_at_max = myvar[t=@max] - myvar
let maxtval = zero_at_max[t=@loc:0.0]

! limit to one point only
set region /i=100/j=50

let dummy = t[gt=myvar,t=`maxtval`]
let tstring = `dummy,return=tend`


Note that my example dataset insists on returning the 't' value with
@loc, not the 'l' index.  This is why I used t=`maxtval` instead of
l= .


Kind regards,
     Hein Zelle


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Dr. Hein Zelle
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