hist {base}

R Documentation

Histograms

Description

hist computes and plots a histogram of the given data values. The histogram cells are intervals of the form [a,b), i.e. they include their left-hand endpoint, but not their right one.

Usage

hist(x, breaks, freq = NULL, col = NULL, border = par("fg"),
     main = paste("Histogram of" , deparse(substitute(x))),
     xlim = range(breaks),  ylim = range(counts, 0),
     xlab = deparse(substitute(x)),  ylab,
     axes = TRUE, plot = TRUE, ...)

Arguments

x	a vector of values for which the histogram is desired.
breaks	either a single number giving the approximate number of cells for the histogram or a vector giving the breakpoints between histogram cells.
freq	a logical vector indicating whether the histogram is to present a representation of frequencies (the default if breaks are equidistant) or relative frequencies (“probabilities”).
col	a colour to be used to fill the bars. The default of NULL yields unfilled bars.
border	the color of the border around the bars.
main, xlab, ylab	these arguments to title have useful defaults here.
xlim, ylim	the range of x and y values with sensible defaults.
plot	logical. If TRUE (default), a histogram is plotted, otherwise a list of breaks and counts is returned.
...	further graphical parameters to title and axis.

Value

a list with components

breaks	the n+1 cell boundaries (= breaks if that was a vector).
counts	n integers; for each cell, the number of x[] inside.
rel.freqs	the relative frequencies
mids	the n cell midpoints; useful for plotting.

Examples

data(islands)
op <- par(mfrow=c(2,2))
hist(islands)
r <- hist(islands, col="gray")
text(r$mids,r$counts,r$counts,adj=c(.5,-.5))

hist(sqrt(islands), br = 12, col="lightblue", border="pink")
##-- For non-equidistant breaks, counts should NOT be graphed unscaled:
r <- hist(sqrt(islands), br = c(4* 0:5,10* 3:5,70,100,140), col='blue1')
text(r$mids, r$rel.fr, r$counts, adj=c(.5,-.5), col='blue3')
par(op)

str(hist(islands, plot= F))
str(hist(islands, br=12, plot= F))

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