Hi, Is there a way to plot non numerical data in R? Specifically, I have an array, say with 1000 entries, where each entry is a string of 4 characters (in any order, 24 possibilities in my case). I would like on the y-axis all the strings that are in the array as labels. The x-axis I would like labeled 0 to 1000. The line is to show how the strings change as we move through the array. (This is essentially a trace plot of a Markov Chain Monte Carlo algorithm. I think essentially I would like an equivalent to plot(myArray, type='l') but with discrete, finite, non-numerical values on the y-axis) Is this possible? Michal.
On Tue, 2007-11-20 at 00:37 +0000, Michal Charemza wrote:> Hi, > > Is there a way to plot non numerical data in R? > > Specifically, I have an array, say with 1000 entries, where each entry > is a string of 4 characters (in any order, 24 possibilities in my > case). I would like on the y-axis all the strings that are in the > array as labels. The x-axis I would like labeled 0 to 1000. The line > is to show how the strings change as we move through the array. > > (This is essentially a trace plot of a Markov Chain Monte Carlo > algorithm. I think essentially I would like an equivalent to > plot(myArray, type='l') but with discrete, finite, non-numerical > values on the y-axis) > > Is this possible? > > Michal.For some pre-existing possibilities, you might want to look at the following CRAN packages: MCMCPack mcmc coda scapeMCMC Alternatively, consider coercing your character values to a factor, predicated upon some relevant ordering. You can then plot the numeric values of the factors for your y axis. Simple example: Y <- sample(LETTERS, 1000, replace = TRUE) plot(1:1000, factor(Y), type = "l", yaxt = "n") axis(2, at = 1:26, labels = LETTERS, cex.axis = 0.75) HTH, Marc Schwartz
Here is one way to plot your data:
# generate 24 cases of 4 letter character strings
x <- expand.grid(c("A", "B"),
c("C","D"), c("E","F"),
c("G","H","I"))
x <- apply(x, 1, paste, collapse='')
# data to plot
y <- factor(sample(x, 200, TRUE))
par(mar=c(5,6,1,1))
plot(seq_along(y), y, yaxt='n', type='l', ylab='')
axis(2, at=seq_along(levels(y)), labels=levels(y), las=2)
On Nov 19, 2007 7:37 PM, Michal Charemza <m.t.charemza at warwick.ac.uk>
wrote:> Hi,
>
> Is there a way to plot non numerical data in R?
>
> Specifically, I have an array, say with 1000 entries, where each entry
> is a string of 4 characters (in any order, 24 possibilities in my
> case). I would like on the y-axis all the strings that are in the
> array as labels. The x-axis I would like labeled 0 to 1000. The line
> is to show how the strings change as we move through the array.
>
> (This is essentially a trace plot of a Markov Chain Monte Carlo
> algorithm. I think essentially I would like an equivalent to
> plot(myArray, type='l') but with discrete, finite, non-numerical
> values on the y-axis)
>
> Is this possible?
>
> Michal.
>
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--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?