Message-ID: <1074798341.5099.94.camel@localhost.localdomain>
Date: 2004-01-22T19:05:41Z
From: Marc Schwartz
Subject: Axes Ticks
In-Reply-To: <4010173D.9040509@yale.edu>
On Thu, 2004-01-22 at 12:32, ivo welch wrote:
> Apologies, basic question on plot.
>
> y <- c(-4,3,-2,1);
> x <- c("time 1", "time 2", "time 3", "time 4");
> plot(x,y, type="b");
>
> of course fails.
> x <- 1:4
> makes it succeed, but then I have too many ticks on my X axis. I want
> exactly 4 tickmarks. It would also be nicer if I could name the ticks.
>
> I looked at ?par and Venables&Ripley, and tried the lab and xaxp
> parameters. I could not figure out how to use them productively. could
> someone please let me know? help appreciated. /iaw
Use 'xaxt' in the call to plot() and then use axis() to control the axis
tick marks and labels:
y <- c(-4, 3, -2, 1)
x <- c(1:4)
# Do not plot the x axis
plot(x, y, type = "b", xaxt = "n")
# Now draw the x axis with text labels
axis(1, at = 1:4, labels = paste("Time", 1:4, sep = " "))
See ?par (xaxt) and ?axis for more information.
You can also use:
plot(x, y, axes = FALSE)
and then use axis(1, ...) and axis(2, ...) if you want to control both
the x and y axes, respectively.
HTH,
Marc Schwartz