Chi-squared Distribution
Maximum likelihood estimation of the degrees of freedom for a chi-squared distribution.
chisq(link = "loglink", zero = NULL)
link, zero |
See |
The degrees of freedom is treated as a parameter to be estimated, and as real (not integer). Being positive, a log link is used by default. Fisher scoring is used.
An object of class "vglmff" (see vglmff-class).
The object is used by modelling functions such as vglm,
and vgam.
Multiple responses are permitted. There may be convergence problems if the degrees of freedom is very large or close to zero.
T. W. Yee
Forbes, C., Evans, M., Hastings, N. and Peacock, B. (2011). Statistical Distributions, Hoboken, NJ, USA: John Wiley and Sons, Fourth edition.
cdata <- data.frame(x2 = runif(nn <- 1000))
cdata <- transform(cdata, y1 = rchisq(nn, df = exp(1 - 1 * x2)),
y2 = rchisq(nn, df = exp(2 - 2 * x2)))
fit <- vglm(cbind(y1, y2) ~ x2, chisq, data = cdata, trace = TRUE)
coef(fit, matrix = TRUE)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.