gg2density {ggplot} | R Documentation

## Grob function: 2d density

### Description

Perform a 2D kernel density estimatation using `kde2d` and

### Usage

    gg2density(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 is another function useful for dealing with overplotting.

Aesthetic mappings that this grob function understands:

- `x`:x position (required)
- `y`:y position (required)

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:

- passed to `ggcontour`, see it for details

### Author(s)

Hadley Wickham <h.wickham@gmail.com>

### See Also

`ggcontour` for another way of dealing with over plotting

### Examples

    m <- ggpoint(ggplot(movies, aesthetics=list(y=length, x=rating)))
    dens <- MASS::kde2d(movies$rating, movies$length)
    densdf <- data.frame(expand.grid(rating = dens$x, length = dens$y), z=as.vector(dens$z))
    ggcontour(m, list(z=z), data=densdf)
    gg2density(m)
    # they don't look the same due to scaling effects on kde2d

[Package ggplot version 0.4.2 Index]