🚧 fix and clarify calculation

Author: victorlin

src/components/tree/phyloTree/helpers.js

@@ -99,16 +99,18 @@ export const setDisplayOrder = ({nodes, focus}) => {
   let incrementer = (_node) => 1;
 
   if (focus) {
-    const numVisible = nodes[0].n.tipCount;
+    const nVisible = nodes[0].n.tipCount;
+    const nTotal = nodes[0].n.fullTipCount;
 
     let yProportionFocused = 0.8;
     // Adjust for a small number of visible tips (n<4)
-    yProportionFocused = Math.min(yProportionFocused, numVisible / 5);
+    yProportionFocused = Math.min(yProportionFocused, nVisible / 5);
     // Adjust for a large number of visible tips (>80% of all tips)
-    yProportionFocused = Math.max(yProportionFocused, numVisible / nodes.length);
+    yProportionFocused = Math.max(yProportionFocused, nVisible / nTotal);
+
+    const yPerFocused = (yProportionFocused * nTotal) / nVisible;
+    const yPerUnfocused = ((1 - yProportionFocused) * nTotal) / (nTotal - nVisible);
 
-    const yPerFocused = (yProportionFocused * nodes.length) / numVisible;
-    const yPerUnfocused = ((1 - yProportionFocused) * nodes.length) / (nodes.length - numVisible);
     incrementer = (() => {
       let previousWasVisible = false;
       return (node) => {