  We provide formulas for the moments of the real and complex noncentral
Wishart distributions of general degrees. The obtained formulas for the real
and complex cases are described in terms of the undirected and directed graphs,
respectively. By considering degenerate cases, we give explicit formulas for
the moments of bivariate chi-square distributions and $2\times 2$ Wishart
distributions by enumerating the graphs. Noting that the Laguerre polynomials
can be considered to be moments of a noncentral chi-square distributions
formally, we demonstrate a combinatorial interpretation of the coefficients of
the Laguerre polynomials.
