[R] x axis point labels

Mark Myatt
Tue, 25 Sep 2001 09:18:11 -0000

Michaell Taylor <michaell.taylor at reis.com>
writes:
>
>I am attempting to manually specify x axis value labels (NOT x axis label as
>in xlab) on a density plot.  Generally speaking, I would like to erase the
>default x axis point labels and replace them with arbitrary x axis point
>labels relating to specific CDF points.
>
>I am sure this can be done, but it isn't obvious to me how.  Has anyone
done
>this before?

Just wrestled with something like this myself and this is the way I did
it:

        1. Set the lab parameter to the number of tickmarks you want on
        the x and y axes. If you have a vector of labels called (e.g.)
        my.labels then use something like:

                par(lab = c(length(my.labels, 5, 7))

        2. Plot without axes (i.e. add the parmeater "axes = false" to
        the plotting function you use top create your chart).

        3. Add axes using the axis() function:

                axis(side = 1, labels = mylabels)
                axis(side = 2)

Here is an example using a time series ... you should get the idea:

        Months <- c("May", "Jun", "Jul",
"Aug", "Sep", "Oct", "Nov",
                    "Dec", "Jan", "Feb",
"Mar", "Apr", "May", "Jun",
                    "Jul")
        WheatI <- c(0.00, 0.97, 0.97, 0.87, 0.74, 0.64, 0.51, 0.28,
                    0.26, 0.18, 0.00, 0.00, 0.00, 0.00, 0.00)

        par(lab = c(length(Months), 3, 7))
        plot(WheatI * 100, type = "s", ylim = c(0, 100), xlab =
"",
             ylab = "%", main = "Irrigated Wheat", bty =
"n",
             axes = FALSE)
        axis(side = 1, labels = Months)
        axis(side = 2)

I hope that helps.

Mark


--
Mark Myatt