Applies a function which calculates a parameter with lower/uper
bounds to groups of data.
group.UCL(x, data, FUN, ...)
Arguments
- x
an `aggregate` compatible formula
- data
a data frame (or list) from which the variables in formula should be taken.
- FUN
the function to apply to each group
- ...
extra params passed on to aggregate
Value
A data frame consisting of one column for each grouping factor plus
three columns for the upper bound, mean and lower bound of the standard error
interval for each level of the grouping factor.
Examples
require(latticeExtra)
with(group.UCL(weight~feed,chickwts,FUN=CI),
segplot(feed~weight.lower+weight.upper,center=weight.mean)
)
require(Hmisc)
with(group.UCL(Temp~Month,airquality,FUN=STDERR),
xYplot(Cbind(Temp.mean,Temp.lower,Temp.upper)~numericScale(Month),type="b",ylim=c(60,90))
)
