From: Deepayan Sarkar <deepayan.sarkar_at_gmail.com>

Date: Thu 18 Aug 2005 - 02:42:06 EST

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 Received on Thu Aug 18 02:47:18 2005

Date: Thu 18 Aug 2005 - 02:42:06 EST

On 8/14/05, Jamieson Cobleigh <cobleigh@gmail.com> wrote:

> I using lattice to make some plots and I want to make the y-axis on

*> some of these plots use a log scale. In the following plot:
**>
**> x <- 1:10
**> y <- 2^x
**> xyplot(log10(y) ~ x)
**>
**> I get tick marks on the y-axis at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0. I
**> would rather have just 3 tick marks at 1.0, 2.0, and 3.0 but labeled
**> 10, 100, and 1000.
**>
**> I know this can be done using the "at" and "labels" parameters to the
**> "x" parameter to the "scales" parameter to the "xyplot" command.
**>
**> xyplot(log10(y) ~ x, scales=list(y=list(at=c(1, 2, 3), labels=c(10,
**> 100, 1000))))
**>
**> My problem is that I am making multiple plots and cannot set the
**> labels on each plot individually. I need to automate the computation
**> of the "at" and "labels" parameters. I think the "axTicks" command
**> can compute the information I need to set "at" and "labels" correctly,
**> but I am having trouble determining how to set its parameters to make
**> it compute the information I need. Perhaps "pretty" might work to,
**> but "axTicks" seems better designed for handling logarithmic axes.
**>
**> Does anyone have any suggestions?
*

The `right' way to do this is

xyplot(y ~ x, scales = list(y = list(log = 10)))

Unfortunately, the labeling for this doesn't use axTicks, it takes the easy way out by using labels of the form "10^2", "10^3", etc. This is partly due to laziness on my part, and also the fact that axTicks doesn't support all the features 'scales' claims to.

My intended `solution' to this (currently vapourware) is to allow the user to specify a function to calculate tick positions and labels. In principle, this could be useful for other transformations, e.g. sqrt for rootograms. I haven't thought through what the API for this would be like, and I don't know when I will get around to actually implementing it.

Deepayan

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 Received on Thu Aug 18 02:47:18 2005

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