R: Add Error Bars to an Existing Plot

ErrBars {DescTools} | R Documentation

## Add Error Bars to an Existing Plot

### Description

Add error bars to an existing plot.

### Usage

    ErrBars(from, to = NULL, pos = NULL, mid = NULL, horiz = FALSE, col = par("fg"),
            lty = par("lty"), lwd = par("lwd"), code = 3, length = 0.05,
            pch = NA, cex.pch = par("cex"), col.pch = par("fg"), bg.pch = par("bg"),
            ...)

### Arguments

`from` | coordinates of points from which to draw (the lower end of the error bars). If `to` is left to `NULL` and `from` is a k x 2 dimensional matrix, the first column will be interpreted as `from` and the second as `to`.
`to` | coordinates of points to which to draw (the upper end of the error bars).
`pos` | numeric, position of the error bars. This will either be the x-coordinate in case of vertical error bars and the y-coordinate in case of horizontal error bars.
`mid` | numeric, position of midpoints. Defaults to the mean of `from` and `to`.
`horiz` | logical, determining whether horizontal error bars are needed (default is FALSE).
`col` | the line color.
`lty` | the line type.
`lwd` | line width.
`code` | integer code, determining where end lines are to be drawn. `code = 0` will draw no end lines, `code = 1` will draw an end line on the left (lower) side at (`x0[i]`, `y0[i]`), `code = 2` on the right (upper) side (`x1[i]`, `y1[i]`) and `code = 3` (default) will draw end lines at both ends.
`length` | the length of the end lines.
`pch` | plotting character for the midpoints. The position of the points is given by `mid`. If `mid` is left to `NULL` the points will be plotted in the middle of `from` and `to`. No points will be plotted if this is set to `NA`, which is the default.
`cex.pch` | the character extension for the plotting characters. Default is `par("cex")`.
`col.pch` | the color of the plotting characters. Default is `par("fg")`.
`bg.pch` | the background color of the plotting characters (if pch is set to 21:25). Default is `par("bg")`.
`...` | the dots are passed to the `arrows` function.

### Details

A short wrapper for plotting error bars by means of `arrows`.

### Author(s)

Andri Signorell <andri@signorell.net>

### See Also

`arrows`, `lines.loess`

### Examples

    par(mfrow=c(2,2))
    b <- barplot(1:5, ylim=c(0,6))
    ErrBars(from=1:5-rep(0.5,5), to=1:5+rep(0.5,5), pos=b, length=0.2)

    # just on one side
    b <- barplot(1:5, ylim=c(0,6))
    ErrBars(from=1:5, to=1:5+rep(0.5,5), pos=b, length=0.2, col="red", code=2, lwd=2)

    b <- barplot(1:5, xlim=c(0,6), horiz=TRUE)
    ErrBars(from=1:5, to=1:5+rep(0.2,5), pos=b, horiz=TRUE,  length=0.2, col="red", code=2, lwd=2)

    par(xpd=FALSE)
    dotchart(1:5, xlim=c(0,6))
    ErrBars(from=1:5-rep(0.2,5), to=1:5+rep(0.2,5), horiz=TRUE, length=0.1)

[Package DescTools version 0.99.38 Index]