tion of <span class="math inline">\(\beta\)</span>. It can also be
worthwhile to subtract the mean from each column of <span class="math inline">\(x\)</span> before
obtaining the QR decomposition, which does not affect the posterior
distribution of <span class="math inline">\(\theta\)</span> or <span class="math inline">\(\beta\)</span> but does affect <span class="math inline">\(\alpha\)</span> and
allows you to interpret <span class="math inline">\(\alpha\)</span> as the expectation of <span class="math i