scatterSmooth: Scatter plot with smooth curve fitted by loess

In mikemeredith/MMmisc: Stuff that Mike wants to have available

Description

Plot and add a smooth curve computed by loess to a scatter plot.

Usage

scatterSmooth(x, y = NULL, data = parent.frame(),
  span = 0.75, degree = 2, family = "gaussian",
  xlab = NULL, ylab = NULL, ylim, evaluation = 50, add = FALSE, CI = NULL,
  col.smooth = "red", lwd.smooth = 1, lty.smooth = 1, ...)

Arguments

x,y	the x and y arguments provide the x and y coordinates for the plot. Any reasonable way of defining the coordinates is acceptable. See the function xy.coords for details.
data	data frame or environment containing the variables.
span	smoothness parameter for loess.
degree	degree of local polynomial used.
family	if "gaussian" fitting is by least-squares, and if family="symmetric" a re-descending M estimator is used.
xlab, ylab	labels for the x and y axes
ylim	y limits of the plot
evaluation	number of points at which to evaluate the smooth curve.
add	if TRUE, the loess line will be added to an existing plot.
CI	the confidence interval to be plotted, or NULL (the default) to suppress plotting of the confidence interval.
col.smooth, lwd.smooth, lty.smooth	colour, line width and line type for the loess smoother line.
...	graphical parameters.

Details

This is identical to stats::scatter.smooth except that: 1. it allows you to specify the colour, width and line type of the loess line; defaults to col="red", lwd=1, lty=1. 2. it suppresses warnings from the loess.smooth function for sparse data sets. 3. with add = TRUE, it allows a loess line to be added to an existing scatterplot.

Value

None

Author(s)

Mike Meredith, 28 Aug 2012, adapted from stats::scatter.smooth.

See Also

loess, scatter.smooth

Examples

require(graphics)
data(trees)

scatterSmooth(trees$Girth, trees$Volume)

with(trees, scatterSmooth(Volume ~ Height))

plot(trees$Volume ~ trees$Girth)
abline(lm(Volume ~ Girth, data = trees), col='blue')
scatterSmooth(trees$Volume ~ trees$Girth, add=TRUE)

mikemeredith/MMmisc documentation built on Nov. 8, 2019, 11:34 p.m.