VGAM (version 0.8-1)

chisq: Chi-squared Distribution

Description

Maximum likelihood estimation of the degrees of freedom for a chi-squared distribution.

Usage

chisq(link = "loge", earg=list())

Arguments

link

Parameter link function. See Links for more choices.

earg

List. Extra argument for the link. See earg in Links for general information.

Value

• An object of class "vglmff" (see vglmff-class). The object is used by modelling functions such as vglm, and vgam.

Details

The degrees of freedom is treated as a parameter to be estimated. It is treated as real and not integer. Being positive, a log link is used by default. Fisher scoring is used.

References

Evans, M., Hastings, N. and Peacock, B. (2000) Statistical Distributions, New York: Wiley-Interscience, Third edition.

See Also

Chisquare. normal1.

Examples

cdata = data.frame(x = runif(nn <- 1000))
cdata = transform(cdata, y = rchisq(nn, df=exp(2 - x)))
fit = vglm(y ~ x, chisq, cdata, trace=TRUE)
coef(fit, matrix=TRUE)