stat_plsmo function

Add a lowess smoother without counfidence bands.

Automatically selects iter=0 for lowess if y is binary, otherwise uses iter=3.

stat_plsmo(
  mapping = NULL,
  data = NULL,
  geom = "smooth",
  position = "identity",
  n = 80,
  fullrange = FALSE,
  span = 2/3,
  fun = function(x) x,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  ...
)

Arguments

• mapping, data, geom, position, show.legend, inherit.aes: see ggplot2 documentation
• n: number of points to evaluate smoother at
• fullrange: should the fit span the full range of the plot, or just the data
• span: see f argument to lowess
• fun: a function to transform smoothed y
• na.rm: If FALSE (the default), removes missing values with a warning. If TRUE silently removes missing values.
• ...: other arguments are passed to smoothing function

Returns

a data.frame with additional columns - y: predicted value

Examples

require(ggplot2)
c <- ggplot(mtcars, aes(qsec, wt))
c + stat_plsmo()
c + stat_plsmo() + geom_point()

c + stat_plsmo(span = 0.1) + geom_point()

# Smoothers for subsets
c <- ggplot(mtcars, aes(y=wt, x=mpg)) + facet_grid(. ~ cyl)
c + stat_plsmo() + geom_point()
c + stat_plsmo(fullrange = TRUE) + geom_point()

# Geoms and stats are automatically split by aesthetics that are factors
c <- ggplot(mtcars, aes(y=wt, x=mpg, colour=factor(cyl)))
c + stat_plsmo() + geom_point()
c + stat_plsmo(aes(fill = factor(cyl))) + geom_point()
c + stat_plsmo(fullrange=TRUE) + geom_point()

# Example with logistic regression
data("kyphosis", package="rpart")
qplot(Age, as.numeric(Kyphosis) - 1, data = kyphosis) + stat_plsmo()

See Also

lowess for loess smoother.