Talk:Scale-inverse-chi-square distribution

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[edit] Request move

The name is more proper without the dashes --Kupirijo 23:16, 31 March 2007 (UTC)

[edit] Other

Shouldn't the mode be \frac{\nu \sigma^2}{\nu-2} because \chi_{\nu}^2(x) is maximized when x = ν − 2

No, the correct denominator for the mode is ν + 2:

1) See "Bayesian Data Analysis, 2nd edition" by Gelman et al., p.574.
2) I have verified that the derivative of the stated probability density function
f(x)=\frac{(\sigma^2\nu/2)^{\nu/2}}{\Gamma(\nu/2)}~ \frac{\exp\left[ \frac{-\nu \sigma^2}{2 x}\right]}{x^{1+\nu/2}}
with respect to x is zero at the stated mode
x_{mode}=\frac{\nu \sigma^2}{\nu+2}
PAR 09:36, 11 July 2006 (UTC)