and y by columns. The vectors must have the same
number of rows.</p>
<!-- row_vector; append_col; (row_vector x, row_vector y); -->
<p></p>
<p><code>row_vector</code> <strong><code>append_col</code></strong><code>(row_vector x, row_vector y)</code><br>
Combine row vectors x and y of any size into another row vector.</p>
<!-- row_vector; append_col; (real x, row_vector y); -->
<p></p>
<p><code>row_vector</code> <strong><code>append_col</code></strong><code>(real x, row_vector y)</code><br>
Append x to the fr