Statistics and Algorithms / Probability Distributions / Chi-Squared |
Parameters |
Degrees of freedom (\(\nu \)) |
Kernel |
\(x^{(\nu - 2) / 2}\exp \left( -x / 2 \right) \) |
Support |
\(\left[ 0,\infty \right) \) |
Mean |
\(\nu \) |
Variance |
\(2 \nu \) |
Main Uses |
Asymptotic distribution. Prior, exact and approximate posterior for the precision (reciprocal of variance) of residuals or other shocks in a model |
Density Function |
%CHISQRDENSITY(x,nu) is the (non-logged) density with nu degrees of freedom at x. |
Tail Probability |
%CHISQR(x,nu) returns the probability that a chi-squared with nu degrees of freedom exceeds x. |
Inverse Tail Probability |
%INVCHISQR(p,nu) returns the critical value for probability p. |
Random Draws |
%RANCHISQR(nu) draws one or more (depending upon the target) independent chi-squareds with NU degrees of freedom |
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