thanks Deepayan, that works great!
2009/6/19 Deepayan Sarkar <deepayan.sar...@gmail.com>: > On 6/18/09, Katharina May <may.kathar...@googlemail.com> wrote: >> Hi there, >> >> sorry for troubling everybody once again, I've got a problem rewriting >> Sarkar's function for >> rewriting the tick locations in a logaritmic way (s. >> http://lmdvr.r-forge.r-project.org/code/Chapter08.R): >> >> His example works for log 2 but I need log e (natural logarithm). My >> problem is that if I replace >> 2 with "e" (using paste()), I get the error message that the location >> isn't a numeric value. > > R doesn't have a constant that represents e, but > > tick.at <- logTicks(exp(lim), loc = c(1, 3)) > > instead of > > tick.at <- logTicks(paste("e^",lim,sep=""), loc = c(1, 3)) > > should give you e^lim. Or, if it makes it easier, > > e <- exp(1) > tick.at <- logTicks(e^lim, loc = c(1, 3)) > > I don't think you need to change the logTicks function. > > -Deepayan > >> Is there any way to get this working somehow or do I have to take a >> different approach? >> >> Thanks, Katharina >> >> Here my failing approach: >> >> require(lattice) >> data(Earthquake, package = "MEMSS") >> >> xscale.components.log <- function(lim, ...) { >> ans <- xscale.components.default(lim = lim, ...) >> tick.at <- logTicks(paste("e^",lim,sep=""), loc = c(1, 3)) >> ans$bottom$ticks$at <- log(tick.at, 2) >> ans$bottom$labels$at <- log(tick.at, 2) >> ans$bottom$labels$labels <- as.character(tick.at) >> ans >> } >> >> logTicks <- function (lim, loc = c(1, 5)) { >> ii <- floor(log(range(lim))) + c(-1, 2) >> main <- paste("e^",(ii[1]:ii[2]),sep="") >> r <- as.numeric(outer(loc, main, "*")) >> r[lim[1] <= r & r <= lim[2]] >> } >> xyplot(accel ~ distance, data=Earthquake, scales = list(log = "e"), >> xscale.components = xscale.components.log, >> >> >> >> >> Here is the original code of Sarkar: >> >> logTicks <- function (lim, loc = c(1, 5)) { >> ii <- floor(log10(range(lim))) + c(-1, 2) >> main <- 10^(ii[1]:ii[2]) >> r <- as.numeric(outer(loc, main, "*")) >> r[lim[1] <= r & r <= lim[2]] >> } >> xscale.components.log2 <- function(lim, ...) { >> ans <- xscale.components.default(lim = lim, ...) >> tick.at <- logTicks(2^lim, loc = c(1, 3)) >> ans$bottom$ticks$at <- log(tick.at, 2) >> ans$bottom$labels$at <- log(tick.at, 2) >> ans$bottom$labels$labels <- as.character(tick.at) >> ans >> } >> >> ______________________________________________ >> r-h...@r-project.org 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. >> > -- Time flies like an arrow, fruit flies like bananas. ______________________________________________ R-help@r-project.org 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.
