cutils literal notranslate"><span class="pre">n_r_vec_grid</span></code> - Number of <span class="math notranslate nohighlight">\(\mathbf{r}\)</span> vectors to keep in each direction. For example, <code class="code docutils literal notranslate"><span class="pre">n_r_vec_grid</span> <span class="pre">=</span> <span class="pre">[3,</span> <span class="pre">3,</span> <span class="pre">3]</span></code> keeps all <span class="math notranslate nohighlight">\(\mathbf{r} \in \{ r_1, r, 2, r_3\}, -1 \leq r_i \leq 1