e. The spectral density of the model is <span class="math display">\[\begin{align*}
h_{\boldsymbol{W}}(\boldsymbol{w}) = \sum_{k=1}^m \pi_k
\frac{\Gamma(\alpha_{1k}+ \cdots + \alpha_{dk})}{\prod_{i=1}^d
\Gamma(\alpha_{ik})} \left(1-\sum_{i=1}^{d-1}
w_i\right)^{\alpha_{dk}-1}\prod_{i=1}^{d-1} w_{i}^{\alpha_{ik}-1}
\end{align*}\]</span> The argument <code>param</code> is thus a <span class="math inline">\(d \times m\)</span> matrix of coefficients, while
the argument for the <span class="math inline">\(m\)</s