Display a weighted histogram

Calculate the counts of the weighted values in specified bins and optionally display either a frequency or density histogram.

Usage

weighted.hist(x,w,breaks="Sturges",col=NULL,plot=TRUE,
 freq=TRUE,ylim=NA,ylab=NULL,xaxis=TRUE,...)

Arguments

x: A vector of numeric values
w: A vector of weights at least as long as x.
breaks: The endpoints of the ranges into which to count the weighted values.
col: An optional vector of colors for the bars of the histogram.
plot: Whether to plot a histogram.
freq: Whether to plot counts or densities.
ylim: The limits of the plot ordinate.
ylab: Label for the ordinate.
xaxis: Whether to display an X axis.
...: additional arguments passed to barplot.

Details

weighted.hist calculates the weighted counts of values falling into the ranges specified by breaks. Instead of counting each value as 1, it counts the corresponding value in w (the weight).

breaks may be specified by a monotonically increasing vector of numbers that are interpreted as the endpoints of the ranges, a single number representing the number of ranges desired or the name of the function to calculate the ranges (see hist). If a vector of numbers is passed that does not include all values in x, the user is warned.

Value

A list containing:

breaks - The endpoints of the intervals

counts - The weighted counts

density - The weighted counts divided by their sum.

mids - The midpoints of the intervals and the bars displayed.

xname - the name of x.

Author

Jim Lemon and Hadley Wickham - thanks to Ben Graf for asking for a custom x axis option and Martin Maechler for fixing the barplot problem

Examples

 testx<-sample(1:10,300,TRUE)
 testw<-seq(1,4,by=0.01)
 weighted.hist(testx,testw,breaks=1:10,main="Test weighted histogram")