[R] plot function creating bars instead of lines

[R. Michael Weylandt]

It is indeed the fact you're plotting factors, but unless you say what
"as intended" is, it's hard to provide exactly what you're seeking.
Perhaps this will help though:

X <- factor(sample(letters[1:5], 15, TRUE))
Y <- rnorm(15)

dats <- data.frame(X, Y)

plot(Y ~ X, data = dats) # No good
plot(X ~ Y, data = dats) # Also probably not what you want

plot(Y ~ as.numeric(X), data = dats) # Good but ugly lables

plot(Y ~ as.numeric(X), data = dats, xaxt = "n", xlab = "X")
axis(1, at = seq_along(levels(X)), labels = levels(X)) # Good

But perhaps easier is

library(ggplot2)
qplot(X,Y, dats)

Michael

On Mon, Apr 23, 2012 at 11:25 AM, la mer <melissarosenkranz at gmail.com> wrote:
> Hello,
>
> I am having a problem where code that plots lines using a different data
> frame plots bars with the current data frame (I am intended to plot lines).
> The code specifies lines (see below), so I can't figure out why the results
> are bars. I suspect that it may have something to do with the fact that in
> the data frame where the code worked as intended, the both variables
> specifying different lines were numeric, whereas in the current data frame
> one of those variables (challenge) is a factor with 2 levels. Any
> suggestions for getting this to plot as intended would be much appreciated.
>
> Thank you!
>
> ************ This is meant to plot a separate line for each subject for each
> challenge*************
> for (subj in unique(lab.samples$subid)) {
>        #par(new=T)
>        plot.new()
>        par(mfrow=c(2,1))
>        par(mfg=c(1,1))
>        plot(data=lab.samples, subset=(subid==subj), cortisol ~ Sample, type='n',
>                main=paste('Cortisol and Amylase for subject ', as.character(subj)))
>
>        for ( t in unique(subset(lab.samples,subid==subj)$challenge) ) {
>                par(mfg=c(1,1))
>                lines(data=lab.samples, subset=(subid==subj & challenge==t),
>                        cortisol ~ Sample, type='b', pch=as.character(t), col=rainbow(2)[t])
>        }
>        par(mfg=c(2,1))
>        plot(data=lab.samples, subset=(subid==subj), amylase ~ Sample, type='n')
>        for ( t in unique(subset(lab.samples,subid==subj)$challenge) ) {
>                par(mfg=c(2,1))
>                lines(data=lab.samples, subset=(subid==subj & challenge==t),
>                        amylase ~ Sample, type='b', pch=as.character(t), col=heat.colors(2)[t])
>        }
> }
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/plot-function-creating-bars-instead-of-lines-tp4580765p4580765.html
> Sent from the R help mailing list archive at Nabble.com.
>
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