CODEWITHSUNDEEP
rplot
Iftikhar
Iftikhar

Reputation: 667

How to write labels in barplot on x-axis with duplicated names?

I am trying to make a simple barplot but i have a problem that I have duplicated names on x-axis. So when ever I am trying to write names on x-axis it does not show complete string. I have following data

x <- c(1.8405917,0.3265986,1.5723623,464.7370299,0.0000000,3.2235716,
       3.1223534, 7.0999787, 1.7122258,3.2005524,3.7531266,469.4436828)

and I am using barplot

barplot(x,xlab=c("AA/AA","AA/CC","AA/AC","AA/NC","CC/AA","CC/CC","CC/AC",
                 "CC/NC","AC/AA","AC/CC","AC/AC","AC/NC"))

But it does not work. I also used 

axis()

But it does not work as well.

Thanks in advance.

Upvotes: 18

Views: 81904

Answers (4)

Gavin Simpson
Gavin Simpson

Reputation: 174788

No, xlab is for providing a label for the entire x-axis of the plot, not for labelling the individual bars.

barplot() takes the labels for the bars from the names of the vector plotted (or something that can be derived into a set of names).

> names(x) <- c("AA/AA", "AA/CC", "AA/AC", "AA/NC", "CC/AA", "CC/CC", "CC/AC",
+               "CC/NC", "AC/AA", "AC/CC", "AC/AC", "AC/NC")
> barplot(x)
> ## or with labels rotated, see ?par
> barplot(x, las = 2)

Edit: As @Aaron mentions, barplot() also has a names.arg to supply the labels for the bars. This is what ?barplot has to say:

names.arg: a vector of names to be plotted below each bar or group of bars. If this argument is omitted, then the names are taken from the names attribute of height if this is a vector, or the column names if it is a matrix.

Which explains the default behaviour if names.arg is not supplied - which is to take the names from the object plotted. Which usage is most useful for you will mainly be a matter of taste. Not having the row/column/names might speed code up slightly, but many of R's functions will take the names attribute (or similar, e.g. row names) directly from objects so you don't have to keep providing labels for plotting/labelling of results etc.

Upvotes: 23

IRTFM
IRTFM

Reputation: 263301

The way to use axis() is to capture the midpoints, which is what the barplot function returns. See ?barplot:

 mids <- barplot(x, xlab="")

 axis(1, at=mids, labels=c("AA/AA","AA/CC","AA/AC","AA/NC","CC/AA","CC/CC",
                           "CC/AC","CC/NC","AC/AA","AC/CC","AC/AC","AC/NC"), 
      las=3)

Upvotes: 5

bill_080
bill_080

Reputation: 4750

Try this:

barplot(x, cex.names=0.7,
        names.arg=c("AA/AA","AA/CC","AA/AC","AA/NC","CC/AA","CC/CC","CC/AC",
                    "CC/NC","AC/AA","AC/CC","AC/AC","AC/NC"))

Upvotes: 4

Aaron - mostly inactive
Aaron - mostly inactive

Reputation: 37734

xlab should be names.arg. See ?barplot for details.

Upvotes: 11

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