mvctm (version 1.2)

permcluster: Generates a Permuted Data Set

Description

This function generates a permuted data set that can be used to perform a permutation test for a variance component for 2-level, 3-level or 4-level data.

Usage

permcluster(cluster, data, leveltested)

Arguments

cluster

A vector giving the name of the variables in the data frame data to specify the clustering configuration. The order is important. For 2-level data it is a vector of dimension 1 specifying the level 1 cluster. For 3-level data, it is a vector of dimension 2. The first element specifies the level 1 (outer) cluster and the second one specifies the level 2 (inner) cluster. For 4-level data, it is a vector of dimension 3. The first element specifies the level 1 (outer) cluster, the second one specifies the level 2 (middle) cluster, and the last one specifies the level 3 (inner) cluster.

data

A data frame containing the data.

leveltested

An integer giving the level to be tested. It must be 1 for 2-level data, 1 or 2 for 3-level data, and 1, 2 or 3 for 4-level data. It corresponds to the element in cluster.

Value

A data frame that contains the original variables plus 1, 2 or 3 new columns. For 2-level data, a single new column called clusperm1 contains the permuted indices for the level 1 cluster. For 3-level data, two new columns called clusperm1 and clusperm2 contain the permuted indices for the level 1 and level 2 clusters, respectively. For 4-level data, three new columns called clusperm1, clusperm2 and clusperm3 contain the permuted indices for the level 1, level 2, and level 3 clusters, respectively.

Details

This is a utility function that allows to perform a permutation test with another test statistic than the one in the function mvctm.

References

Larocque, D., Nevalainen, J. and Oja, H. (2018). Multivariate Variance Components Tests for Multilevel Data. Les Cahiers du GERAD G-2018-58.

Examples

# NOT RUN {
data(toydata)

# generates a permuted data set with 2-level data

permcluster(cluster=c("classroom"),data=toydata,leveltested=1)

# generates a permuted data set with 4-level data to test for level 2

permcluster(cluster=c("region","school","classroom"),
data=toydata,leveltested=2)

# performing a permutation test with another
# test statistic might look like this

# }
# NOT RUN {
pval=0
# compute the statistic with the original data. Call in stato.
for (i in 1:npermut)
{
pdata=permcluster(cluster=c("classroom"),data=toydata,leveltested=1)
# compute the statistic with pdata using the new column
# clusperm1 instead of classroom as the cluster index.
# call it statp.
pval=pval+(statp>stato)
}
pval/npermut
# }
# NOT RUN {
# }