[Thread Prev][Thread Next][Index]
[ferret_users] Lag induces by a centered derivative method?
- To: ferret_users@xxxxxxxx
- Subject: [ferret_users] Lag induces by a centered derivative method?
- From: Fabrice Vauclair <vauclairf@xxxxxxxxxx>
- Date: Wed, 04 Apr 2007 12:13:05 +1200
- Dkim-signature: v=0.5; a=rsa-sha1; c=relaxed/simple; d=niwa.co.nz; s=blizzard; t=1175645586; bh=Gfw6YG0zG7VlQrs3nrojhQ39q3M=; h=Received: Message-ID:Date:From:User-Agent:MIME-Version:To:Subject: Content-Type:Content-Transfer-Encoding:X-Greylist:X-Scanned-By; b=T faHKWStKLGFikCDf1gpq7Ji5AIOdIyDpp9pHtmSfO/RK1eYPmodwmfdX15lhXeGHXhr u0uK3CojEda9UtDYpkGd6YujemQIVVzjr1LYc5RvxK3Hyt9g4aQ8u2xZwJYS
- Sender: owner-ferret_users@xxxxxxxxxxxxx
- User-agent: Thunderbird 1.5.0.8 (X11/20061107)
Dear Ferret users,
I calculated the temporal derivative of SST for a seasonal cycle
(monthly values) and I think that it induces a one month lag which seems
to be an artefact of the derivative method (centered derivative @DDC).
Does anyone already had this kind of problem?
To solve that, I wanted to find the polynomial (f(t)=At^3+Bt^2+Ct +D)
that best fit my data, then calculate the derivative function
(f'(t)=3At^2+2Bt+C) and work with f'(t).
So come my questions:
- Does it make sense that calculating a temporal derivative could induce
a lag that is a artefact of the method (centered derivative)?
- How can I find, using Ferret, the polynomial that best fit my function?
Thank you very much in advance for your help,
Kind regards,
Fabrice
[Thread Prev][Thread Next][Index]
Contact Us
Dept of Commerce /
NOAA /
OAR /
PMEL /
TMAP
Privacy Policy | Disclaimer | Accessibility Statement