Re: [ferret_users] Pick up the only values at the peaks

[Steve Hankin <Steven.C.Hankin@xxxxxxxx>]

To get the maximum value over a time range use VAR[T=lo:hi@max]

To find all of the times that a time series exceeds a particular threshold use @EVN

To find all places where the function has a local maximum define its second derivative to be a new variable using two LET commands and the @DDC (or @DDF or @DDB) transformation.  Then use an IF test (or @EVN again) to locate the places where the 2nd derivative is negative.

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Seon Tae Kim wrote:

Hi All
Now since I can not access the mail archives sever for ferret help,
I need your help.
I have time series data of SST anomaly.
I want to pick up the values at the peak of the time series curve.
Good ways never come into my head.

Could anyone help me with it?
Thank you...
-Seon Tae-

-- 
Steve Hankin, NOAA/PMEL -- Steven.C.Hankin@xxxxxxxx
7600 Sand Point Way NE, Seattle, WA 98115-0070
ph. (206) 526-6080, FAX (206) 526-6744

"The only thing necessary for the triumph of evil is for good men
to do nothing." -- Edmund Burke