   species       b_0    b_3
1 Fagaceae Quercus chrysolepis  2.22 -0.427</code></pre></div><p></p><hr><code>rc = 1 - ((1)/(1 + exp(b_0 + b_3 * log(gn) + b_4 * (dsob/hst))))</code><ul><li><p><code>rc [ft ft-1]</code> - crown ratio</p></li>
<li><p><code>hst [ft]</code> - total height of the stem</p></li>
<li><p><code>dsob [in]</code> - diameter of the stem, outside bark at breast height</p></li>
<li><p><code>gn [ft2 acre-1]</code> - stand-level basal area</p></li>
</ul><p><b>Model Parameters</b></p><div class=