gggroup {ggplot} | R Documentation

## Grob function: groups

### Description

Create multiple of grobs based on id aesthetic.

### Usage

    gggroup(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

This grob function provides a general means of creating multiple grobs based on groups in the data. This is useful if you want to fit a separate smoother for each group in the data.

You will need an id variable in your aesthetics list with determines how the data is broken down.

Aesthetic mappings that this grob function understands:

- `x`:x position (required)
- `y`:y position (required)
- `id`:
- any other grobs used by the grob function you choose

These can be specified in the plot defaults (see `ggplot`) or in the `aesthetics` argument. If you want to modify the position of the points or any axis options, you will need to add a position scale to the plot. These functions start with `ps`, eg. `pscontinuous` or `pscategorical`

Other options:

- `grob`:grob function to use for subgroups
- anything else used by the grob function you choose

### Author(s)

Hadley Wickham <h.wickham@gmail.com>

### Examples

    p <- ggplot(mtcars, aesthetics=list(y=wt, x=qsec, id=cyl, colour=cyl))
    gggroup(p)
    gggroup(p, grob="density")
    gggroup(p, grob="histogram", aes=list(fill=cyl))
    gggroup(ggpoint(p), grob="smooth", se=FALSE, span=1)
    gggroup(ggpoint(p), aes=list(id=cyl, size=cyl), grob="smooth", span=1)

[Package ggplot version 0.4.2 Index]