'><a href='https://rdrr.io/r/base/matrix.html'>matrix</a></span><span class='op'>(</span><span class='fu'><a href='https://rdrr.io/r/base/unlist.html'>unlist</a></span><span class='op'>(</span><span class='va'>x_train</span><span class='op'>)</span>, ncol <span class='op'>=</span> <span class='fl'>1</span><span class='op'>)</span>
<span class='va'>x_test</span> <span class='op'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/matrix.html'>matrix</a></span><span class='op'>(</span><span class='f