intxplot
Interaction plot, with an option to print standard error bars.
Interaction plot, with an option to print standard error bars. There is an option to offset group lines to prevent the bars from overprinting.
- Keywords
- dplot
Usage
intxplot(x, data=sys.parent[1], groups.in,
scales,
key.length=1,
key.lines,
key=TRUE,
trace.factor.name=deparse(substitute(groups.in)),
x.factor.name=x.factor,
xlab=x.factor.name,
main=list(main.title, cex=main.cex),
condition.name="condition",
panel="panel.intxplot",
summary.function="sufficient",
se,
...,
data.is.summary=FALSE,
main.title=paste(
"Interactions of", trace.factor.name, "and",
x.factor.name,
if (length(x[[3]]) > 1)
paste("|", condition.name.to.use)),
main.cex=1.5)panel.intxplot(x, y, subscripts, groups, type = "l", ..., se, cv=1.96,
offset.use=(!missing(groups) && !missing(se)),
offset.scale=2*max(as.numeric(groups)),
offset=
as.numeric(groups[match(levels(groups), groups)]) / offset.scale,
rug.use=offset.use)
Arguments
- x
For
intxplot
, a formula with a factor as the predictor variable. Forpanel.intxplot
, standard argument for panel functions.- data
data.frame, as used in
xyplot
.- groups.in
groups.in
, as used inxyplot
.- scales
Optional, additional arguments for the standard
scales
inxyplot
.- key.length
Number of columns in the key.
- key.lines
default value for the
lines
argument ofkey
.- key
logical. If
TRUE
, draw the key.- trace.factor.name
Name of the grouping variable.
- x.factor.name
name of the dependent variable.
- xlab
as in
xyplot
, defaults to the name of the predictor variable from the formula.- main
as in
xyplot
. Defaults to themain.title
argument.- panel
as in
xyplot
. Defaults to the"panel.intxplot"
.- condition.name
name of the conditioning variable.
- summary.function
The default
sufficient
finds the mean, standard deviation, and sample size of the response variable for each level of the conditioning factor. Seesufficient
.- se
standard errors to be passed to
panel.intxplot
.se
Missing, logical, or a numeric vector. If missing orFALSE
, standard errors are not plotted. Ifse=TRUE
inintxplot
, the standard errors are calculated from the sufficient statistics for each group as the group's standard deviation divided by the square root of the group's observation count. Ifse
is numeric vector, it is evaluated in the environment of the sufficient statistics. these
argument topanel.intxplot
must be numeric.- …
In
intxplot
, arguments forpanel.intxplot
. Inpanel.intxplot
, arguments forpanel.superpose
.- data.is.summary
logical, defaults to
FALSE
under the assumption that the input data.frame is the original data and theintxplot
function will generate the summary information (primarily standard deviationsd
and number of observationsnobs
for each group). WhenTRUE
, the standard error calculation assumes variablessd
andnobs
are in the dataset.- main.title
Default main title for plot.
- main.cex
Default character expansion for main title.
- y, subscripts, groups, type
Standard arguments for panel functions.
- cv
critical value for confidence intervals. Defaults to 1.96.
- offset.use
logical. If
TRUE
, offset the endpoints of each group.- offset.scale
Scale number indicating how far apart the ends of the groups will be placed. Larger numbers make them closer together.
- offset
Actual numbers by which the end of the groups are offset from their nominal location which is the
as.numeric
of the group levels.- rug.use
logical. If
TRUE
, display a rug for the endpoints of each group.
Value
"trellis"
object.
See Also
Examples
# NOT RUN {
## This uses the same data as the HH Section 12.13 rhizobium example.
data(rhiz.clover)
## interaction plot, no se
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover)
## interaction plot, individual se for each treatment combination
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover, se=TRUE)
## Rescaled to allow the CI bars to stay within the plot region
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover, se=TRUE,
ylim=range(rhiz.clover$Npg))
## interaction plot, common se based on ANOVA table
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover,
se=sqrt(sum((nobs-1)*sd^2)/(sum(nobs-1)))/sqrt(5))
## Rescaled to allow the CI bars to stay within the plot region
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover,
se=sqrt(sum((nobs-1)*sd^2)/(sum(nobs-1)))/sqrt(5),
ylim=range(rhiz.clover$Npg))
## change distance between endpoints
intxplot(Npg ~ strain, groups=comb, data=rhiz.clover,
se=TRUE, offset.scale=20)
## When data includes the nobs and sd variables, data.is.summary=TRUE is needed.
intxplot(Npg ~ strain, groups=comb,
se=sqrt(sum((nobs-1)*sd^2)/(sum(nobs-1)))/sqrt(5),
data=sufficient(rhiz.clover, y="Npg", c("strain","comb")),
data.is.summary=TRUE,
ylim=range(rhiz.clover$Npg))
# }