Superimpose a function.

Usage

stat_function(mapping = NULL, data = NULL, geom = "path", position = "identity",
  fun, n = 101, args = list(), ...)

Arguments

fun
function to use
n
number of points to interpolate along
args
list of additional arguments to pass to fun
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: xx's along a grid yvalue of function evaluated at corresponding x

Description

Superimpose a function.

Aesthetics

stat_function understands the following aesthetics (required aesthetics are in bold):

  • y

Examples

x <- rnorm(100) base <- qplot(x, geom = "density") base + stat_function(fun = dnorm, colour = "red")

base + stat_function(fun = dnorm, colour = "red", arg = list(mean = 3))

# Plot functions without data # Examples adapted from Kohske Takahashi # Specify range of x-axis qplot(c(0, 2), stat = "function", fun = exp, geom = "line")

ggplot(data.frame(x = c(0, 2)), aes(x)) + stat_function(fun = exp)

# Plot a normal curve ggplot(data.frame(x = c(-5, 5)), aes(x)) + stat_function(fun = dnorm)

# With qplot qplot(c(-5, 5), stat = "function", fun = dnorm, geom = "line")

# Or qplot(c(-5, 5), geom = "blank") + stat_function(fun = dnorm)

# To specify a different mean or sd, use the args parameter to supply new values ggplot(data.frame(x = c(-5, 5)), aes(x)) + stat_function(fun = dnorm, args = list(mean = 2, sd = .5))

# Two functions on the same plot f <- ggplot(data.frame(x = c(0, 10)), aes(x)) f + stat_function(fun = sin, colour = "red") + stat_function(fun = cos, colour = "blue")

# Using a custom function test <- function(x) {x ^ 2 + x + 20} f + stat_function(fun = test)