statmod (version 1.5.0)

meanT: Mean t-Statistic Between Two Groups of Growth Curves

Description

The mean-t statistic of the distance between two groups of growth curves.

Usage

meanT(y1, y2)

Value

numeric vector of length one containing the mean t-statistic.

Arguments

y1

matrix of response values for the first group, with a row for each individual and a column for each time. Missing values are allowed.

y2

matrix of response values for the second group. Must have the same number of columns as y1. Missing values are allowed.

Author

Gordon Smyth

Details

This function computes the pooled two-sample t-statistic between the response values at each time, and returns the mean of these values weighted by the degrees of freedom. This function is used by compareGrowthCurves.

See Also

compareGrowthCurves, compareTwoGrowthCurves

Examples

y1 <- matrix(rnorm(4*3),4,3)
y2 <- matrix(rnorm(4*3),4,3)
meanT(y1,y2)

data(PlantGrowth)
compareGrowthCurves(PlantGrowth$group,as.matrix(PlantGrowth$weight))
# Can make p-values more accurate by nsim=10000