# qboxplot: Quantile-Based Boxplots In qboxplot: Quantile-Based Boxplot

## Description

Produce quantile-based box-and-whisker plot(s) of the given (grouped) values.

## Usage

 ```1 2 3 4 5``` ```qboxplot(x, range=1.5, probs=c(0.25,0.5,0.75), qtype=7, data=parent.frame(), width=NULL, varwidth=FALSE, outline=TRUE, names=NULL, plot=TRUE, border=par("fg"), col=NULL, log="", pars=list(boxwex=0.8, staplewex=0.5, outwex=0.5), horizontal=FALSE, add=FALSE, at=NULL, ...) ```

## Arguments

 `x` a formula, such as `y ~ grp`, where `y` is a numeric vector of data values to be split into groups according to the grouping variable `grp` (usually a factor), or a data frame specifying data from which the boxplots are to be produced. `range` this determines how far the plot whiskers extend out from the box. If `range` is positive, the whiskers extend to the most extreme data point which is no more than `range` times the difference between the value of the upper hinge and the value of the lower hinge from the box. A value of zero causes the whiskers to extend to the data extremes. `probs` numeric vector of values in [0,1] specifying the percentiles of the upper hinge, the midpoint (usually the median) and the lower hinge. `qtype` an integer between 1 and 9 indicating which one of the nine quantile algorithms to use (see `quantile`). `data` a data.frame (or list) from which the variables in `formula` should be taken. `width` a vector giving the relative widths of the boxes making up the plot. `varwidth` if `varwidth` is `TRUE`, the boxes are drawn with widths proportional to the square-roots of the number of observations in the groups. `outline` if `outline` is `FALSE`, the outliers are not drawn. `names` group labels which will be printed under each boxplot. `plot` if `TRUE` then a boxplot is produced. If not, the summaries which the boxplots are based on are returned. `border` an optional vector of colours for the outlines of the boxplots. The values in `border` are recycled if the length of `border` is less than the number of plots. `col` if `col` is non-null it is assumed to contain colors to be used to colour the bodies of the box plots. By default they are in the background colour. `log` character indicating if x or y or both coordinates should be plotted in log scale. `pars` a list of (potentially many) more graphical parameters. `horizontal` logical indicating if the boxplots should be horizontal; default `FALSE` means vertical boxes. `add` logical, if `TRUE` add boxplot to current plot. `at` numeric vector giving the locations where the boxplots should be drawn; defaults to `1:n` where `n` is the number of boxes. `...` other arguments (see `boxplot`).

## Value

List with the following components:

 `stats` a matrix, each column contains the extreme of the lower whisker, the lower hinge, the midpoint, the upper hinge and the extreme of the upper whisker for one group/plot. `n` a vector with the number of observations in each group. `out` the values of any data points which lie beyond the extremes of the whiskers. `group` a vector of the same length as `out` whose elements indicate to which group the outlier belongs. `names` a vector of names for the groups.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21``` ```#Example 1 data = data.frame(a=runif(10), b=runif(10), c=runif(10)) qboxplot(data, range=1.3, probs=c(0.2,0.5,0.7), qtype=6) #Example 2 qboxplot(count~spray, data=InsectSprays, col="lightgray") #Example 3 rb = qboxplot(decrease~treatment, data=OrchardSprays, log="y", col="bisque") title("") rb #Example 4 mat = cbind(Uni05=(1:100)/21, Norm=rnorm(100), "5T"=rt(100,df=5), Gam2=rgamma(100,shape=2)) qboxplot(as.data.frame(mat)) #Example 5 data = c(102,133,136,139,142,144,146,151,160,174) qboxplot(data.frame(data), range=1.5, probs=c(0.25,0.5,0.75), qtype=1, ylim=c(100,220), horizontal=TRUE) ```

qboxplot documentation built on May 2, 2019, 8:35 a.m.