rotating axis labels in R

r rotate axis labels, use the las argument that is a numeric value indicating the orientation of the tick mark labels and any other text added to a plot after its initialization.

The options are as follows:

Parallel to the axis (the default, 0),

Horizontal (1),

Perpendicular to the axis (2),

Vertical (3).

For example:

data(mtcars)
barplot(mtcars$cyl, col=mtcars$gear, las = 1)

Output:

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