span class="fu">vec2mat</span><span class="op">(</span><span class="fl">1</span><span class="op">:</span><span class="fl">10</span>, diag<span class="op">=</span><span class="cn">TRUE</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>      [,1] [,2] [,3] [,4]</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [1,]    1    2    3    4</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [2,]    2    5    6    7</span>
<span class="r-out co