class.ind                package:nnet                R Documentation

Generates Class Indicator Matrix from a Factor

Description:

     Generates a class indicator function from a given factor.

Usage:

     class.ind(cl)

Arguments:

      cl: factor or vector of classes for cases. 

Value:

     a matrix which is zero except for the column corresponding to the
     class.

References:

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

Examples:

     # The function is currently defined as
     class.ind <- function(cl)
     {
       n <- length(cl)
       cl <- as.factor(cl)
       x <- matrix(0, n, length(levels(cl)) )
       x[(1:n) + n*(unclass(cl)-1)] <- 1
       dimnames(x) <- list(names(cl), levels(cl))
       x
     }

