interactionPlots {s20x}R Documentation

Interactions Plot for Two-way Analysis of Variance

Description

Displays data with intervals for each combination of the two factors and shows the mean differences between levels of the first factor for each level of the second factor. Note that there should be more than one observation for each combination of factors.

Usage

interactionPlots(y, ...)
## Default S3 method:
interactionPlots (y, fac1 = NULL, fac2 = NULL, xlab = NULL, xlab2 = NULL, ylab = NULL, data.order=TRUE, exlim=0.1, jitter=0.02, conf.level=0.95, interval.type="tukey", pooled=TRUE, tick.length=0.1, interval.distance=0.2, col.width = 2/3, xlab.distance=0.1, xlen=1.5, ylen=1, ...)
## S3 method for class 'formula':
interactionPlots (y, data, xlab = NULL, xlab2 = NULL, ylab = NULL, data.order = TRUE, exlim=0.1, jitter=0.02, conf.level=0.95, interval.type="tukey", pooled=TRUE, tick.length=0.1, interval.distance=0.2, col.width = 2/3, xlab.distance=0.1, xlen=1.5, ylen=1, ...)

Arguments

y either a formula of the form: y~fac1+fac2 where y is the response and fac1 and fac2 are the two explanatory variables used as factors, or a single response vector
fac1 if 'y' is a vector, then fac1 contains the levels of factor 1 which correspond to the y value
fac2 if 'y' is a vector, then fac1 contains the levels of factor 2 which correspond to the y value
data an optional data frame containing the variables in the model.
xlab an optional label for the x-axis. If not specified the name of fac1 will be used.
xlab2 an optional label for the lines. If not specified the name of fac2 will be used.
ylab An optional label for the y-axis. If not specified the name of y will be used.
data.order if TRUE the levels of fac1 and fac2 will be set to unique(fac1) and unique(fac2) respectively.
exlim provide extra limits.
jitter the amount of horizontal jitter to show in the plot. The actual jitter is determined as the function is called, and will likely be different each time the function is used.
conf.level confidence level of the intervals.
interval.type four options for intervals appearing on plot: "tukey", "hsd", "lsd" or "ci".
pooled two options: pooled or unpooled standard deviation used for plotted intervals.
tick.length size of tick, in inches.
interval.distance distance, as a fraction of the column width, between the points and interval. This is in addition to the extra space allocated for the jitter.
col.width width of a factor `column', as a fraction of the space between the centres of two columns.
xlab.distance distance of x-axis labels from bottom of plot, as a fraction of the overall height of the plot.
xlen, ylen xxx
... optional arguments.

See Also

"summary2way".

Examples

data(mtcars)
interactionPlots(wt~vs+gear, mtcars)

## note this usage is deprecated
data(mtcars)
with(mtcars, interactionPlots(wt,vs,gear))

[Package s20x version 3.1-5 Index]