/span> <span class='va'>LETTERS</span><span class='op'>[</span><span class='fl'>1</span><span class='op'>:</span><span class='fl'>7</span><span class='op'>]</span><span class='op'>)</span></span>
<span class='r-in'></span>
<span class='r-in'><span class='va'>p1</span> <span class='op'>&lt;-</span> <span class='fu'>polar_init</span><span class='op'>(</span><span class='va'>data</span>, x <span class='op'>=</span> <span class='va'>x</span><span class='op'>)</span></span>
<span class='r-in'><span class='va'>p1