R: Transformation: density estimate

layer_densities {ggvis} | R Documentation

## Transformation: density estimate

### Description

`transform_density` is a data transformation that computes a kernel density estimate from a dataset. `layer_density` combines `transform_density` with `mark_path` and `mark_area` to display a smooth line and its standard errror.

### Usage

    layer_densities(vis, ..., kernel = "gaussian", adjust = 1,
      density_args = list(), area = TRUE)

### Arguments

`vis` | The visualisation to modify
`...` | Visual properties, passed on to `props`.
`kernel` | Smoothing kernel. See `density` for details.
`adjust` | Multiple the default bandwidth by this amount. Useful for controlling wiggliness of density.
`density_args` | Other arguments passed on to `compute_density` and thence to `density`.
`area` | Should there be a shaded region drawn under the curve?

### Examples

    # Basic density estimate
    faithful %>% ggvis(~waiting) %>% layer_densities()
    faithful %>% ggvis(~waiting) %>% layer_densities(area = FALSE)

    # Control bandwidth with adjust
    faithful %>% ggvis(~waiting) %>% layer_densities(adjust = .25)
    faithful %>% ggvis(~waiting) %>%
      layer_densities(adjust = input_slider(0.1, 5))

    # Control stroke and fill
    faithful %>% ggvis(~waiting) %>%
      layer_densities(stroke := "red", fill := "red")

    # With groups
    PlantGrowth %>% ggvis(~weight, fill = ~group) %>% group_by(group) %>%
      layer_densities()
    PlantGrowth %>% ggvis(~weight, stroke = ~group) %>% group_by(group) %>%
      layer_densities(strokeWidth := 3, area = FALSE)

[Package ggvis version 0.4.3 Index]