Implement weilHeight utility

ref xenharmonic-devs/scale-workshop#675

documentation/BUILTIN.md

@@ -752,6 +752,9 @@ Convert value to a boolean. Vectorizes over arrays.
 ### void()
 Get rid of expression results. `void(++i)` increments the value but doesn't push anything onto the scale.
 
+### weilHeight(*x*)
+Calculate the Weil height of the interval. Natural logarithm of the maximum of numerator or denominator.
+
 ### wellTemperament(*commaFractions*, *comma = 81/80*, *down = 0*, *generator = 3/2*, *period = 2*)
 Generate a well-temperament by cumulatively modifying the pure fifth `3/2` (or a given generator) by fractions of the syntonic/given comma.
 

src/parser/__tests__/vector-broadcasting.spec.ts

@@ -392,4 +392,13 @@ describe('SonicWeave vector broadcasting', () => {
       [-1, NaN],
     ]);
   });
+
+  it('has a broadcasting Weil height', () => {
+    const ln5 = sw0D`weilHeight 3/5`;
+    expect(ln5.valueOf()).toBeCloseTo(Math.log(5));
+
+    const [ln2, ln3] = sw1D`[2, 3/2] weilHeight`;
+    expect(ln2.valueOf()).toBeCloseTo(Math.LN2);
+    expect(ln3.valueOf()).toBeCloseTo(Math.log(3));
+  });
 });

src/stdlib/prelude.ts

@@ -159,6 +159,10 @@ riff oddLimitOf(x, equave = 2) {
   const noEquaves = x ~% equave^(x dot %logarithmic(equave));
   return numerator(noEquaves) max denominator(noEquaves);
 }
+riff weilHeight(x) {
+  "Calculate the Weil height of the interval. Natural logarithm of the maximum of numerator or denominator.";
+  return (tenneyHeight x ~+ log(labs x)) ~/ 2;
+}
 riff hypot(...args) {
   "Calculate the square root of the sum of squares of the arguments.";
   return sum(map(a => a ~^ 2, args)) ~/^ 2;