plspm (version 0.2-2)

rebus.test: Permutation Test for REBUS Multi-Group Comparison

Description

Performs permutation tests for comparing pairs of groups from a REBUS object.

Usage

rebus.test(pls, reb, Y = NULL)

Arguments

pls

Object of class "plspm" returned by plspm.

reb

Object of class "rebus" returned by either rebus.pls or it.reb.

Y

Optional dataset (matrix or data frame) used when argument dataset=NULL inside pls.

Value

• An object of class "rebus.test", basically a list containing the results of each pair of compared classes. In turn, each element of the list is also a list with the results for the path coefficients, loadings, and GoF index.

Details

A permutation test on path coefficients, loadings, and GoF index is applied to the classes obtained from REBUS, by comparing two classes at a time. That is to say, a permutation test is applied on pair of classes. The number of permutations in each test is 100. The number of classes handled by rebus.test is limited to 6. When the object pls does not contain a data matrix (i.e. pls$data=NULL), the user must provide the data matrix or data frame in Y.

References

Chin, W.W. (2003) A permutation procedure for multi-group comparison of PLS models. In: Vilares, M., Tenenhaus, M., Coelho, P., Esposito Vinzi, V., Morineau, A. (Eds.) PLS and Related Methods - Proceedings of the International Symposium PLS03. Decisia, pp. 33-43.

See Also

rebus.pls, local.models

Examples

## example of rebus analysis with simulated data
  data(sim.data)
  ## Calcualte plspm
  sim.inner <- matrix(c(0,0,0,0,0,0,1,1,0),3,3,byrow=TRUE)
  dimnames(sim.inner) <- list(c("Price","Quality","Satisfaction"),
                            c("Price","Quality","Satisfaction"))
  sim.outer <- list(c(1,2,3,4,5),c(6,7,8,9,10),c(11,12,13)) 
  sim.mod <- c("A","A","A")  ## reflective indicators
  sim.global <- plspm(sim.data, inner=sim.inner, 
                      outer=sim.outer, modes=sim.mod)
  sim.global
  ## Cluster analysis on residuals of global model
  sim.res.clus <- res.clus(sim.global)
  ## Iterative steps of REBUS algorithm on 2 classes
  rebus.sim <- it.reb(sim.global, sim.res.clus, nk=2, 
                     stop.crit=0.005, iter.max=100)
  sim.permu <- rebus.test(sim.global, rebus.sim)
  sim.permu
  sim.permu$test_1_2
  ## or equivalently
  sim.permu[[1]]