| HMSkew {logmult} | R Documentation |
Specify a Skew-Symmetric Association in a gnm Model Formula
Description
A function of class "nonlin" to specify a van der Heijden & Mooijaart (1995) skew-symmetric
association in the formula argument to gnm.
Usage
HMSkew(row, col, inst = NULL)
Arguments
row |
the levels of the row variable |
col |
the levels of the column variable |
inst |
a positive integer specifying the instance number of the term |
Details
This function is used by hmskew to fit skew-symmetric models proposed by
van der Heijden & Mooijaart (1995) and their variants. It can be used directly to fit custom
variants of the model not supported by hmskew.
This function combines its arguments in the following way:
HMSkew(i, j) = \nu_i \mu_j - \mu_i \nu_j
where HMSkew(i, j) is the skew association for the cell at the intersection of row i and column j of
the table. See reference for mathematical details.
Value
A list with the required components of a "nonlin" function:
predictors |
the expressions passed to |
term |
a function to create a deparsed mathematical expression of the term, given labels for the predictors. |
call |
the call to use as a prefix for parameter labels. |
Author(s)
Milan Bouchet-Valat
References
van der Heijden, P.G.M., and Mooijaart, A. (1995). Some new log bilinear models for the analysis of asymmetry in a square contingency table. Sociol. Methods and Research 24, 7-29.
See Also
Examples
# See ?hmskew.