QQplot {UsingR} | R Documentation

## Creates a qqplot with shaded density estimate

### Description

Creates a qqplot of two variables along with graphs of their densities, shaded so that the corresponding percentiles are clearly matched up.

### Usage

    QQplot(x, y, n = 20, xsf = 4, ysf = 4, main = "qqplot", xlab = deparse(substitute(x)), ylab = deparse(substitute(y)), pch = 16, pcol = "black", shade = "gray", ...)

### Arguments

`x` | The x variable
`y` | The y variable
`n` | number of points to plot in qqplot.
`xsf` | scale factor to adjust size of x density graph
`ysf` | scale factor to adjust size of y density graph
`main` | title
`xlab` | label for x axis
`ylab` | label for y axis
`pch` | plot character for points in qqplot
`pcol` | color of plot character
`shade` | shading color
`...` | extra arguments passed to `plot.window`

### Details

Shows density estimates for the two samples in a qqplot. Meant to make this useful plot more transparent to first-time users of quantile-quantile plots.

This function has some limitations: the scale factor may need to be adjusted; the code to shade only shaded trapezoids, and does not completely follow the density.

### Value

Produces a graphic

### Author(s)

John Verzani

### See Also

`qqplot`, `qqnorm`

### Examples

    x = rnorm(100)
    y = rt(100, df=3)
    QQplot(x,y)

[Package UsingR version 0.1-4 Index]