Sorry I didn't read the question properly. Please disregard, my mind was elsewhere.
Tom > -----Original Message----- > From: Mulholland, Tom > Sent: Thursday, 13 January 2005 10:52 AM > To: Dr Carbon; [email protected] > Subject: RE: [R] Finding seasonal peaks in a time series.... > > > You might find breakpoints in strucchange helpful > > Tom > > > -----Original Message----- > > From: Dr Carbon [mailto:[EMAIL PROTECTED] > > Sent: Thursday, 13 January 2005 6:19 AM > > To: [email protected] > > Subject: [R] Finding seasonal peaks in a time series.... > > > > > > I have a seasonal time series. I want to calculate the annual mean > > value of the time series at its peak > > > > (say the mean of the three values before the peak, the > peak, and the > > three values after the peak). > > > > The peak of the time series might change cycle slightly from > > year to year. > > > > # E.g., > > nPts <- 254 > > foo <- sin((2 * pi * 1/24) * 1:nPts) > > foo <- foo + rnorm(nPts, 0, 0.05) > > bar <- ts(foo, start = c(1980,3), frequency = 24) > > plot(bar) > > start(bar) > > end(bar) > > > > # I want to find the peak value from each year, and then > get the mean > > of the values on either side. > > # So, if the peak value in the year 1981 is > > max.in.1981 <- max(window(bar, start = c(1981,1), end = c(1981,24))) > > # e.g, cycle 7 or 8 > > window(bar, start = c(1981,1), end = c(1981,24)) == max.in.1981 > > # E.g. if the highest value in 1981 is in cycle 8 I want > > mean.in.1981 <- mean(window(bar, start = c(1981,5), end = > c(1981,11))) > > plot(bar) > > points(ts(mean.in.1981, start = c(1981,8), frequency = 24), col = > > "red", pch = "+") > > > > > > Is there a way to "automate" this for each year. > > > > How can I return the cycle of the max value by year? > > > > Thanks in advance. -DC > > > > ______________________________________________ > > [email protected] mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
