Here is a simple approach:
data <- read.table("test-data.txt")
deriv <- diff(data$V2) / diff(data$V1)
times <- (data$V1[-1] + data$V1[-3545])/2
plot(times, deriv, type="l")
Another approach is to smooth the original data and then obtain derivatives
from the smooth
Ravi.
____________________________________________________________________
Ravi Varadhan, Ph.D.
Assistant Professor,
Division of Geriatric Medicine and Gerontology
School of Medicine
Johns Hopkins University
Ph. (410) 502-2619
email: rvarad...@jhmi.edu
----- Original Message -----
From: Yogesh Tiwari <yogesh....@googlemail.com>
Date: Monday, November 22, 2010 5:14 pm
Subject: [R] how to calculate derivative
To: r-help <r-h...@stat.math.ethz.ch>
> Dear R Users,
>
> I have trend of two time series of CO2 each 10 years of data. One is
> varying
> weekly and another is bi-weekly. I want to calculate Growth rate ppmv
> / year
> of these CO2 trends. Therefore I want to calculate time derivative
> ppmv /
> year.
>
> How to do it in R?
>
> Here I attached example data file, I would appreciate if any one
> kindly can
> help on it.
>
> Thanks,
>
> Regards,
> Yogesh
> ______________________________________________
> R-help@r-project.org mailing list
>
> PLEASE do read the posting guide
> and provide commented, minimal, self-contained, reproducible code.
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