>#    </span>
<span class="co">#    </span>
<span class="co"># </span>
<span class="co"># &lt;!-- ## Numerical evalation in R --&gt;</span>
<span class="co"># </span>
<span class="co"># &lt;!-- ```{r} --&gt;</span>
<span class="co"># &lt;!-- sparsify &lt;- function(x) { --&gt;</span>
<span class="co"># &lt;!--   if (requireNamespace("Matrix", quietly = TRUE)) { --&gt;</span>
<span class="co"># &lt;!--       return(Matrix::Matrix(x, sparse = TRUE)) --&gt;</span>
<span class="co"># &lt;!--       ##return(Matr