In the parameterization used here, \(W\) \(\sim\) \(W(nu,V)\), \(E[W]=nuV\).
If you want to use an Inverted Wishart prior, you must invert the location matrix
before calling rwishart
, e.g.
\(\Sigma\) \(\sim\) IW(nu,V); \(\Sigma^{-1}\) \(\sim\) \(W(nu,V^{-1})\).