Rotating x axis labels in R for barplot

Question

I am trying to get the x axis labels to be rotated 45 degrees on a barplot with no luck. This is the code I have below:

barplot(((data1[,1] - average)/averag         


        

Answer 1

You can simply pass your data frame into the following function:

rotate_x <- function(data, column_to_plot, labels_vec, rot_angle) {
    plt <- barplot(data[[column_to_plot]], col='steelblue', xaxt="n")
    text(plt, par("usr")[3], labels = labels_vec, srt = rot_angle, adj = c(1.1,1.1), xpd = TRUE, cex=0.6) 
}

Usage:

rotate_x(mtcars, 'mpg', row.names(mtcars), 45)

You can change the rotation angle of the labels as needed.

Answer 2

EDITED ANSWER PER DAVID'S RESPONSE:

Here's a kind of hackish way. I'm guessing there's an easier way. But you could suppress the bar labels and the plot text of the labels by saving the bar positions from barplot and do a little tweaking up and down. Here's an example with the mtcars data set:

x <- barplot(table(mtcars$cyl), xaxt="n")
labs <- paste(names(table(mtcars$cyl)), "cylinders")
text(cex=1, x=x-.25, y=-1.25, labs, xpd=TRUE, srt=45)

Answer 3

use optional parameter las=2 .

barplot(mytable,main="Car makes",ylab="Freqency",xlab="make",las=2)

Answer 4

You can use ggplot2 to rotate the x-axis label adding an additional layer

theme(axis.text.x = element_text(angle = 90, hjust = 1))

Answer 5

You may use

par(las=2) # make label text perpendicular to axis

It is written here: http://www.statmethods.net/graphs/bar.html

Answer 6

In the documentation of Bar Plots we can read about the additional parameters (...) which can be passed to the function call:

...    arguments to be passed to/from other methods. For the default method these can 
       include further arguments (such as axes, asp and main) and graphical 
       parameters (see par) which are passed to plot.window(), title() and axis.

In the documentation of graphical parameters (documentation of par) we can see:

las
    numeric in {0,1,2,3}; the style of axis labels.

    0:
      always parallel to the axis [default],

    1:
      always horizontal,

    2:
      always perpendicular to the axis,

    3:
      always vertical.

    Also supported by mtext. Note that string/character rotation via argument srt to par does not affect the axis labels.

That is why passing las=2 is the right answer.