ass="p">:</span>
        <span class="c1"># grid is defined in 1/1000 degree; old format</span>
        <span class="n">grid</span> <span class="o">=</span> <span class="s1">&#39;</span><span class="si">{}</span><span class="s1">/</span><span class="si">{}</span><span class="s1">&#39;</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="nb">float</span><span class="p">(</span><span class="n">grid</span><span class="p">)</span> <span class="o">/</span> <span class="