R Graphical Manual

Browse All

Last data update: 2014.03.03

R: Add a Loess or a Spline Smoother

lines.loess

R Documentation

Add a Loess or a Spline Smoother

Description

Add a loess smoother to an existing plot. The function first calculates the prediction of a loess object for a reasonable amount of points, then adds the line to the plot and inserts a polygon with the confidence intervals.

Usage

## S3 method for class 'loess'
lines(x, col = getOption("col1", hblue), lwd = 2, lty = "solid",
      type = "l", n = 100, conf.level = 0.95, args.band = NULL, ...)

## S3 method for class 'smooth.spline'
lines(x, col = getOption("col1", hblue), lwd = 2, lty = "solid",
      type = "l", conf.level = 0.95, args.band = NULL, ...)
## S3 method for class 'SmoothSpline'
lines(x, col = getOption("col1", hblue), lwd = 2, lty = "solid",
      type = "l", conf.level = 0.95, args.band = NULL, ...)

Arguments

`x`	the loess or smooth.spline object to be plotted.
`col`	linecolor of the smoother. Default is DescTools's `col1`.
`lwd`	line width of the smoother.
`lty`	line type of the smoother.
`type`	type of plot, defaults to `"l"`.
`n`	number of points used for plotting the fit.
`conf.level`	confidence level for the confidence interval. Set this to NA, if no confidence band should be plotted. Default is 0.95.
`args.band`	list of arguments for the confidence band, such as color or border (see `DrawBand`).
`...`	further arguments are passed to the smoother (`loess()` or `SmoothSpline()`).

Note

Loess can result in heavy computational load if there are many points!

Author(s)

Andri Signorell <andri@signorell.net>

Examples

par(mfrow=c(1,2))

x <- runif(100)
y <- rnorm(100)
plot(x, y)
lines(loess(y~x))

plot(temperature ~ delivery_min, data=d.pizza)
lines(loess(temperature ~ delivery_min, data=d.pizza))

plot(temperature ~ delivery_min, data=d.pizza)
lines(loess(temperature ~ delivery_min, data=d.pizza), conf.level = 0.99,
            args.band = list(col=SetAlpha("red", 0.4), border="black") )

# the default values from scatter.smooth
lines(loess(temperature ~ delivery_min, data=d.pizza,
            span=2/3, degree=1, family="symmetric"), col="red")

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DescTools)
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DescTools/lines.loess.Rd_%03d_medium.png", width=480, height=480)
> ### Name: lines.loess
> ### Title: Add a Loess or a Spline Smoother
> ### Aliases: lines.loess lines.smooth.spline lines.SmoothSpline
> ### Keywords: math aplot
> 
> ### ** Examples
> 
> par(mfrow=c(1,2))
> 
> x <- runif(100)
> y <- rnorm(100)
> plot(x, y)
> lines(loess(y~x))
> 
> plot(temperature ~ delivery_min, data=d.pizza)
> lines(loess(temperature ~ delivery_min, data=d.pizza))
> 
> plot(temperature ~ delivery_min, data=d.pizza)
> lines(loess(temperature ~ delivery_min, data=d.pizza), conf.level = 0.99,
+             args.band = list(col=SetAlpha("red", 0.4), border="black") )
> 
> # the default values from scatter.smooth
> lines(loess(temperature ~ delivery_min, data=d.pizza,
+             span=2/3, degree=1, family="symmetric"), col="red")
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>