Plot Group Means and Confidence Intervals
Plot group means and confidence intervals.
plotmeans(formula, data=NULL, subset, na.action,
bars=TRUE, p=0.95, minsd=0, minbar, maxbar,
xlab=names(mf)[2], ylab=names(mf)[1], mean.labels=FALSE,
ci.label=FALSE, n.label=TRUE, text.n.label="n=",
digits=getOption("digits"), col="black", barwidth=1,
barcol="blue", connect=TRUE, ccol=
col, legends=names(means), xaxt, use.t=TRUE,
lwd=par("lwd"), ...)formula |
symbolic expression specifying the outcome (continuous) and grouping variable (factor). See lm() for details. |
data |
optional data frame containing the variables in the model. |
subset |
an optional vector specifying a subset of observations to be used in the fitting process. |
na.action |
a function which indicates what should happen when the data contain ‘NA’s. See lm() for details. |
bars |
a logical value indicating whether confidence interval bars should be plotted. Defaults to TRUE. |
p |
confidence level for error bars. Defaults to 0.95. |
minsd |
minumum permitted value for the standard deviation within
each factor level. Any standard deviation estimates smaller than
|
minbar |
minumum allowed value for bar ends. If specified,
values smaller than |
maxbar |
maximum allowed value for bar ends. If specified,
values larger than |
xlab |
x-axis label. |
ylab |
y-axis label. |
mean.labels |
either a logical value indicating whether the circles representing the group means should be replaced with text giving the actual mean values or a vector containing labels to use instead. Defaults to FALSE. |
ci.label |
a logical value indicating whether text giving the actual interval end values should be placed at the end of each confidence interval bar. Defaults to FALSE. |
n.label |
a logical value indicating whether text giving the number of observations in each group should should be added to the plot. |
text.n.label |
Prefix text for labeling observation counts. Defaults to "n=". |
digits |
number of significant digits to use when displaying mean or confidince limit values. |
col |
color of cicles marking group means. Default is "black". |
barwidth |
linewidth of interval bars and end marks. Default is 1. |
barcol |
color of interval bars and end marks. Default is "blue". |
connect |
either a logical value indicating whether the means of each group should be connected by a line, or a list of vectors giving the index of bars that should be connected by a line. Defaults to TRUE. |
ccol |
color of lines used to connect means. Defaults to the same color as "col". |
legends |
vector containing strings used to label groups along the x axis. Defaults to group names. |
xaxt |
A character which specifies the axis type. Specifying ‘"n"’ causes an axis to be set up, but not plotted. |
use.t |
a logical value indicating whether the t distribution
should be used to compute confidence intervals. If |
lwd |
Width of connecting lines |
... |
optional plotting parameters. |
Gregory R. Warnes greg@warnes.net
# library(gplots)
# show comparison with boxplot
data(state)
plotmeans(state.area ~ state.region)
# show some color and mean labels
plotmeans(state.area ~ state.region,
mean.labels=TRUE, digits=-3,
col="red", connect=FALSE)
# show how to specify which means should be connected
plotmeans(state.area ~ state.region, connect=list(1:2, 3:4),
ccol="red", pch=7 )
# more complicated example showing how to show an interaction
data(esoph)
par(las=2, # use perpendicular axis labels
mar=c(10.1,4.1,4.1,2.1), # create enough space for long x labels
mgp=c(8,1,0) # move x axis legend down to avoid overlap
)
plotmeans(ncases/ncontrols ~ interaction(agegp , alcgp, sep =" "),
connect=list(1:6,7:12,13:18,19:24),
barwidth=2,
col="dark green",
data=esoph,
xlab="Age Group and Alcohol Consumption",
ylab="# Cases / # Controls",
ylim = c(-.9,1.4),
main=c("Fraction of Cases for by Age and Alcohol Consumption",
"Ile-et-Vilaine Esophageal Cancer Study")
)
abline(v=c(6.5, 12.5, 18.5), lty=2)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.