My understanding is that the main point of your post was how to get times on the X axis. hopefully at this point its clear how to do that and you can come up with some algorithm to put whatever points you want on.
Here is a slight generalization although you will likely have to generalize it further. > library(zoo) > library(chron) > tt <- c("23:05:02", "23:10:02", "23:15:03", "23:20:03", "23:25:03", + "23:30:03", "23:35:03", "23:40:03", "23:45:04", "23:50:04", "23:55:03", + "23:55:03") > x <- c(0.575764, 0.738379, 0.567414, 0.663436, 0.599834, 0.679571, + 0.88141, 0.868848, 0.969271, 0.878968, 0.990972, 0.990972) > z <- zoo(x, times(tt)) > mn <- times("23:00:00") > mx <- times("23:55:00") > n <- 12 > xt <- times(seq(mn, mx, length = n)) > xt <- times(unique(sub("..$", "00", xt))) > plot(z, xaxt = "n") > axis(1, xt, sub(":00$", "", xt)) > R.version.string [1] "R version 2.4.0 Patched (2006-10-24 r39722)" > packageDescription("zoo")$Version [1] "1.2-1" > packageDescription("chron")$Version [1] "2.3-9" > On 11/8/06, Carmen Meier <[EMAIL PROTECTED]> wrote: > Gabor Grothendieck schrieb: > > Is the problem how to produce an axis with a given minimum tick, > > maximum tick and given number of ticks? In that case try this > yes but ... ;-) > I started with an plain R gui > > library(zoo) > library(chron) > # input data > # z is from original example > mn <- times("23:00:00") > mx <- times("23:55:00") > n <- 12 > z <-(1:50) > xt <- times(seq(mn, mx, length = n)) > plot(z, xaxt = "n") > axis(1, xt, sub(":00$", "", xt)) > > > The result is an X-axes with 23:00 at the left side nothing else at the > x-axis Not for me. It gives ticks all along the x axis for me. I have placed the entire self contained code above just to be sure. > That`s just the same problem as I got with further trials of my own > and a minor problem will be sub(":00$", "", xt)) if > times(seq(mn, mx, length = n)) will not result > xx:yy:00 values only (f.e n=17) > > Regards Carmen > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.