ac{\partial g(\boldsymbol{\beta})}{\partial \boldsymbol{\beta}}\)</span> is <span class="math inline">\(p \times 1\)</span> and <span class="math inline">\(var(\boldsymbol{\beta})\)</span> is <span class="math inline">\(p \times p\)</span>, so <span class="math inline">\(var[g(\boldsymbol{\beta})]\)</span> is a scalar value.</p>
<p>A <span class="math inline">\(p \times p\)</span> matrix of <span class="math inline">\(var{(\boldsymbol{\beta})}\)</span> is obtained by <code>summary(fit)$cov.unscaled</code> w