# hdr.boxplot: Highest Density Region Boxplots In robjhyndman/hdrcde: Highest Density Regions and Conditional Density Estimation

## Description

Calculates and plots a univariate highest density regions boxplot.

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16``` ```hdr.boxplot( x, prob = c(99, 50), h = hdrbw(BoxCox(x, lambda), mean(prob)), lambda = 1, boxlabels = "", col = gray((9:1)/10), main = "", xlab = "", ylab = "", pch = 1, border = 1, outline = TRUE, space = 0.25, ... ) ```

## Arguments

 `x` Numeric vector containing data or a list containing several vectors. `prob` Probability coverage required for HDRs `density`. `h` Optional bandwidth for calculation of density. `lambda` Box-Cox transformation parameter where ```0 <= lambda <= 1```. `boxlabels` Label for each box plotted. `col` Colours for regions of each box. `main` Overall title for the plot. `xlab` Label for x-axis. `ylab` Label for y-axis. `pch` Plotting character. `border` Width of border of box. `outline` If not TRUE, the outliers are not drawn. `space` The space between each box, between 0 and 0.5. `...` Other arguments passed to plot.

## Details

The density is estimated using kernel density estimation. A Box-Cox transformation is used if `lambda!=1`, as described in Wand, Marron and Ruppert (1991). This allows the density estimate to be non-zero only on the positive real line. The default kernel bandwidth `h` is selected using the algorithm of Samworth and Wand (2010).

Hyndman's (1996) density quantile algorithm is used for calculation.

nothing.

Rob J Hyndman

## References

Hyndman, R.J. (1996) Computing and graphing highest density regions. American Statistician, 50, 120-126.

Samworth, R.J. and Wand, M.P. (2010). Asymptotics and optimal bandwidth selection for highest density region estimation. The Annals of Statistics, 38, 1767-1792.

Wand, M.P., Marron, J S., Ruppert, D. (1991) Transformations in density estimation. Journal of the American Statistical Association, 86, 343-353.

`hdr.boxplot.2d`, `hdr`, `hdr.den`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```# Old faithful eruption duration times hdr.boxplot(faithful\$eruptions) # Simple bimodal example x <- c(rnorm(100,0,1), rnorm(100,5,1)) par(mfrow=c(1,2)) boxplot(x) hdr.boxplot(x) # Highly skewed example x <- exp(rnorm(100,0,1)) par(mfrow=c(1,2)) boxplot(x) hdr.boxplot(x,lambda=0) ```