M.fct {cta}R Documentation

Marginalizing Matrix Based on Strata Information

Description

Creates the marginalizing matrix MM using strata information found in input variable strata. That is, MpMp gives the marginal probabilities corresponding to the levels of factor strata.

Usage

M.fct(strata, ncells = length(strata))

Arguments

strata

The vector that gives the stratum membership identifier.

ncells

Number of contingency table cells. Default: ncells = length(strata).

Value

M.fct returns the marginalizing matrix M.

Note

Marginals are ordered according to the levels of factor strata.

Examples:

V1 V2 y
b yes 15
a no 12
a yes 13
b yes 5
b no 1

M1 <- M.fct(V1)
M1 %*% y

[,1]
a 25
b 21

M2 <- M.fct(V2)
M2 %*% y

[,1]
no 13
yes 33

M12 <- M.fct(paste(V1, V2))
M12 %*% y

[,1]
a no 12
a yes 13
b no 1
b yes 20

Author(s)

Joseph B. Lang

References

Lang, J. B. (2004) Multinomial-Poisson homogeneous models for contingency tables, Annals of Statistics, 32, 340–383.

Examples

M.fct(rep(1, 9))
M.fct(seq(1, 9))
M.fct(c(1, 1, 2, 3, 3))

[Package cta version 1.3.0 Index]