chisq {VGAM} | R Documentation

## 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.

### 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.

### Value

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

### Note

There may be convergence problems if the degrees of freedom is very large.

### Author(s)

T. W. Yee

### References

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

### See Also

`Chisquare`. `normal1`.

### Examples

    y = rchisq(n=200, df=exp(2))
    fit = vglm(y ~ 1, chisq)
    coef(fit, matrix=TRUE)
    Coef(fit)

[Package VGAM version 0.7-9 Index]