getBurt {cabootcrs}  R Documentation 
Converting a data matrix into a Burt matrix
Description
getBurt
recodes a data matrix from one format (n objects by p variables,
counts for distinct combinations of p variables, contingency table) into a Burt matrix,
or extracts a subset of a Burt matrix for selected variables
Usage
getBurt(
Xinput,
input = "nbyp",
Jk = NULL,
maxcat = NULL,
varandcat = TRUE,
vars = NULL
)
Arguments
Xinput 
A data matrix, in the form of a data frame or similar

input 
The format of the input matrix:
 "nbyp"
An n individuals/objects/data points by p categorical variables matrix,
where each row is a different data point and each column contains the category
for that data point on that variable, where these categories can be numbers, strings or factors
 "nbypcounts"
Similar to the above, but each row represents all of the data points taking
the same combination of categories, and the first column contains the count for this combination
(hence the name used here is a bit of a misnomer, but it emphasises the similarities to an n by p)
 "indicator"
An indicator matrix, similar to the n by p matrix except that a variable with J_k categories
is represented by J_k columns and a data point taking the ith category has 1 in the ith
of these columns and a zero in the others
 "Burt"
A Burt matrix, symmetrical and blockdiagonal with each block being a
contingency table for a pair of variables

Jk 
See convert

maxcat 
See convert

varandcat 
See convert

vars 
A list of the variable numbers to be used in the Burt matrix, if only a subset is wanted.
If not all variables are wanted and the input is not n by p then Jk must be specified.

Value
A Burt matrix, symmetrical and blockdiagonal with each block being a contingency table for a pair of variables
See Also
Other conversion functions:
convert()
,
getCT()
,
getdoubled()
,
getindicator()
Examples
nishburt < getBurt(NishData)
nishburtvars1to3 < getBurt(NishData,vars=1:3)
nishburtvars2and4 < getBurt(nishburt,input="Burt",Jk=rep(3,4),vars=c(2,4))
[Package
cabootcrs version 2.1.0
Index]