[R] Changing the x-axis labels in plot()

[Marc Schwartz (via MN)]

On Thu, 2006-02-23 at 15:35 +0000, michael watson (IAH-C) wrote:
> Hi
> 
> Hopefully this one isn't in the manual or I am about to get shot :-S

Bang  ;-)

> One of my colleagues wants a slightly strange graph.  We basically have
> a data matrix, and she wants to plot, for each row, the values in the
> row as points on the graph.  The following code draws the graph just
> fine:
> 
> plot(row(d)[,3:9],d[,3:9])


If I am understanding correctly what you want, you could alternatively
use:

  boxplot(as.data.frame(t(d[, 3:9])))

which provides a somewhat different approach to visualizing the data.
There are other methods as well of course.

> So as there are 12 rows in my matrix, there are 12 columns of points,
> which is what she wants.
> 
> However, she wants the x-axis labelled with the row names, not with
> 1,2,3,4,5 etc
> 
> I can figure out from reading par() how to turn off the default drawing
> of the numerical labels, but how do I use the row names instead?
> 
> Thanks
> Mick


Try:

  plot(row(d)[,3:9], d[,3:9], xaxt = "n")


You can then use the axis() function to specify the labels and tick mark
positions that you want. See ?axis for more information.

In ?par, see 'xaxt' and 'yaxt', which are also referred to in the
description of the 'axes' argument in ?plot.default.

HTH,

Marc Schwartz