ggplot2 (version 0.9.0)

stat_quantile: Continuous quantiles.

Description

Continuous quantiles.

Usage

stat_quantile(mapping = NULL, data = NULL,
    geom = "quantile", position = "identity",
    quantiles = c(0.25, 0.5, 0.75), formula = y ~ x,
    method = "rq", na.rm = FALSE, ...)

Arguments

quantiles

conditional quantiles of y to calculate and display

formula

formula relating y variables to x variables

method

Quantile regression method to use. Currently only supports rq.

na.rm

If FALSE (the default), removes missing values with a warning. If TRUE silently removes missing values.

mapping

The aesthetic mapping, usually constructed with aes or aes_string. Only needs to be set at the layer level if you are overriding the plot defaults.

data

A layer specific dataset - only needed if you want to override the plot defaults.

geom

The geometric object to use display the data

position

The position adjustment to use for overlappling points on this layer

...

other arguments passed on to layer. This can include aesthetics whose values you want to set, not map. See layer for more details.

Value

• a data.frame with additional columns:
• quantile
  quantile of distribution

Examples

msamp <- movies[sample(nrow(movies), 1000), ]
m <- ggplot(msamp, aes(y=rating, x=year)) + geom_point()
m + stat_quantile()
m + stat_quantile(quantiles = 0.5)
m + stat_quantile(quantiles = seq(0.1, 0.9, by=0.1))

# Doesn't work.  Not sure why.
# m + stat_quantile(method = rqss, formula = y ~ qss(x), quantiles = 0.5)

# Add aesthetic mappings
m + stat_quantile(aes(weight=votes))

# Change scale
m + stat_quantile(aes(colour = ..quantile..), quantiles = seq(0.05, 0.95, by=0.05))
m + stat_quantile(aes(colour = ..quantile..), quantiles = seq(0.05, 0.95, by=0.05)) +
  scale_colour_gradient2(midpoint=0.5, low="green", mid="yellow", high="green")

# Set aesthetics to fixed value
m + stat_quantile(colour="red", size=2, linetype=2)

# Use qplot instead
qplot(year, rating, data=movies, geom="quantile")