a>  <span class="dt">int</span>&lt;<span class="kw">lower</span>=<span class="dv">0</span>, <span class="kw">upper</span>=N&gt; N_test;</span>
<span id="cb4-6"><a href="#cb4-6" aria-hidden="true" tabindex="-1"></a>}</span>
<span id="cb4-7"><a href="#cb4-7" aria-hidden="true" tabindex="-1"></a><span class="kw">transformed data</span> {</span>
<span id="cb4-8"><a href="#cb4-8" aria-hidden="true" tabindex="-1"></a>  <span class="dt">int</span> N_train = N - N_test;</span>
<span id="cb4-9"><a href="#cb4-9" aria