orthopoly {MCAvariants}

Orthogonal polynomials

Description

This function is called from the function omca. It allows the analyst to compute the orthogonal polynomials of each ordered categorical variable. The number of the polynomials is equal to the variable category less one. The function computes the polynomial transformation of the ordered categorical variable.

Usage

orthopoly(marginals, scores)

Arguments

scores

The ordered scores of an ordered variable. By default mj=NULL, the natural scores (1,2,...) are computed.

marginals

The marginals, relative frequencies of the ordered variable.

Value

Describe the value returned

B

the matrix of the orthogonal polynomials without the trivial polynomial.

Note

Note that the sum of the marginals of the ordered variables should be one. At the end, the various polynomial matrices will be stored in a super-diagonal matrix.

Author(s)

Rosaria Lombardo and Eric J Beh

References

Beh EJ and Lombardo R 2014 Correspondence analysis, Theory, Practice and New Strategies. Wiley.

Examples

orthopoly(marginals=c(.1,.2,.3,.2,.2), scores=c(1,2,3,4,5))