Logical value indicating whether to treat values as discrete (suitable for character vectors and factors) or continuous (suitable for numeric vectors).
breaks
A single positive integer value giving the number of histogram classes to evenly split the values in x into, or a numeric vector explicitly giving the boundaries of the histogram classes.
ylim
Limits of hte y-axis.
space
The proportion of the total distance on the x-axis allocated to each 'xylophone' which should be left blank.