Approximate number of contingency tables
Approximate number of contingency tables with specified marginal totals.
good(x, method = "D", ...)
- An integer-valued matrix (with no
- The method to use; one of
D. See details section
- Further arguments (notably
n), passed to
All formulae and terminology taken from Good 1976. The letters A-D
are from the approximations given on pages 1167 and 1168.
Note This function will accept matrices with any
entries, but a warning is given. The number of permissable boards
will be less than the number of permissible contingency tables
considered by Good.
The approximations are intended to provide rough-and-ready upper
bounds for boards that have a few
Method A is the exact answer, given by
no.of.boards(). Do not use this on large matrices!
Methods B, C, and D give (according to
Good) increasingly accurate approximations to the exact answer.
- I. J. Good 1976. On the Application of Symmetric Dirichlet Distributions and Their Mixtures to Contingency Tables. The Annals of Statistics 4(6):1159--1189
a <- matrix(1,15,15) good(a,"B") good(a,"C") good(a,"D") #identical to answer given by method "C"