e">\(\beta\)</span> is a <span class="math inline">\(K\)</span>-vector of coefficients.
Presuming <span class="math inline">\(N \geq K\)</span>, we can exploit the fact that any design matrix,
<span class="math inline">\(x\)</span> can be decomposed using the thin QR decomposition into an
orthogonal matrix <span class="math inline">\(Q\)</span> and an upper-triangular matrix <span class="math inline">\(R\)</span>, i.e. <span class="math inline">\(x = Q R\)</span>. See the reference manual for a definition o