a factor (required) whose levels will form the x
axis.
response
a numeric variable giving the response.
group
grouping factor (optional) whose levels will form
groups of bars for each level of x.factor.
split
logical. Should groups of bars be displayed back to back.
See details below.
col
default color(s) for bars.
angle
default angle of shading lines.
density
default density of shading lines.
lc, uc
logical. Should upper or lower CI be drawn?
legend
logical. Should a legend be included?
ncol
number of columns to use for legend.
leg.lab
legend labels for trace factors.
x.leg, y.leg
optional values to over ride the default legend
placement.
cex.leg
character expansion value for legend labels.
bty
line type of bounding box for legend. Defaults to
'none'.
space
set spacing for bars.
err.width
set width of whiskers for error bars.
err.col
color for error bars. Defaults to "black".
err.lty
line type for error bars.
bg
background color of legend.
fun
the function to compute the summary statistic.
Should return a single real value. Defaults to mean with NA
values removed.
ci.fun
the functions to compute the CI. Should return a
vector of length 2 defining the lower and upper limits of the
CI's. Defaults to the mean +/- 1 standard error, with NA
values removed.
ylim
range of y axis.
xpd
defualts to xpd=FALSE (in contrast to barplot)
to cut off the range of data plotted.
data
an optional data frame.
subset
an optional expression indicating the subset of the
rows of 'data' that should be used in the plot.
...
further graphical parameters. See barplot() for
additional options.
Details
Plots a response as a function of treatment (factor) combinations for
one-way and higher designs. This is a "wrapper" function for barplot
that adds confidence intervals - barplot should be consulted for
details. Note that the option "beside=TRUE" from barplot is
hardcoded and that the default for value xpd is FALSE. If the option
split is specified, the response associated with the second
grouping factor will be made negative and displayed back-to-back with
the first.
See Also
barplot, se
Examples
data(ToothGrowth)
# One way design
bargraph.CI(x.factor = dose, response = len, data = ToothGrowth)
# Two-way design with options
bargraph.CI(dose, len, group = supp, data = ToothGrowth,
xlab = "Dose", ylab = "Growth", cex.lab = 1.5, x.leg = 1,
col = "black", angle = 45, cex.names = 1.25,
density = c(0,20), legend = TRUE)