intPlot: Modified Interactions Plot for Two-way Analysis of Variance

In dafs: Data Analysis for Forensic Scientists

Modified Interactions Plot for Two-way Analysis of Variance

Description

This is a modified version of the function interactionPlots from the s20x library which produces greyscale plots.

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

intPlot(y, ...)
## Default S3 method:
 intPlot(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'
 intPlot(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.

Examples

library(s20x)
data(mtcars)
intPlot(wt~vs+gear, mtcars)

dafs documentation built on April 11, 2022, 5:06 p.m.