gghline {ggplot} | R Documentation

## Grob function: hline

### Description

Add horizontal line(s) to a plot

### Usage

    gghline(plot = .PLOT, aesthetics=list(), ..., data=NULL)

### Arguments

`plot` | the plot object to modify
`aesthetics` | named list of aesthetic mappings, see details for more information
`...` | other options, see details for more information
`data` | data source, if not specified the plot default will be used

### Details

Aesthetic mappings that this grob function understands:

- none

Other options:

- `position`: vertical position(s) to draw lines
- `colour`: line colour
- `size`: line thickness
- `linetype`: line type
- `range`: x (or y if slope infinite) range to draw the line. This is sometimes necessary because ggplot isn't smart enough to calculate the entire range of the data

### Author(s)

Hadley Wickham <h.wickham@gmail.com>

### Examples

    p <- ggplot(mtcars, aesthetics=list(x = wt, y=mpg))
    gghline(ggpoint(p), position=mean(mtcars$mpg), size=2)

[Package ggplot version 0.4.2 Index]