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Histograms
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 .
|
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.
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))