fix issue #1368 euclidLegatoRot

packages/core/euclid.mjs

@@ -10,9 +10,8 @@ https://rohandrape.net/?t=hmt
 This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-import { Pattern, timeCat, register, silence } from './pattern.mjs';
+import { timeCat, register, silence } from './pattern.mjs';
 import { rotate, flatten, splitAt, zipWith } from './util.mjs';
-import Fraction from './fraction.mjs';
 
 const left = function (n, x) {
   const [ons, offs] = n;
@@ -42,29 +41,26 @@ const _bjork = function (n, x) {
 
 export const bjork = function (ons, steps) {
   const inverted = ons < 0;
-  ons = Math.abs(ons);
-  const offs = steps - ons;
-  const x = Array(ons).fill([1]);
-  const y = Array(offs).fill([0]);
-  const result = _bjork([ons, offs], [x, y]);
-  const p = flatten(result[1][0]).concat(flatten(result[1][1]));
-  if (inverted) {
-    return p.map((x) => (x === 0 ? 1 : 0));
-  }
-  return p;
+  const absOns = Math.abs(ons);
+  const offs = steps - absOns;
+  const ones = Array(absOns).fill([1]);
+  const zeros = Array(offs).fill([0]);
+  const result = _bjork([absOns, offs], [ones, zeros]);
+  const pattern = flatten(result[1][0]).concat(flatten(result[1][1]));
+  return inverted ? pattern.map((x) => 1 - x) : pattern;
 };
 
 /**
- * Changes the structure of the pattern to form an euclidean rhythm.
- * Euclidian rhythms are rhythms obtained using the greatest common
+ * Changes the structure of the pattern to form an Euclidean rhythm.
+ * Euclidean rhythms are rhythms obtained using the greatest common
  * divisor of two numbers.  They were described in 2004 by Godfried
- * Toussaint, a canadian computer scientist.  Euclidian rhythms are
+ * Toussaint, a Canadian computer scientist.  Euclidean rhythms are
  * really useful for computer/algorithmic music because they can
  * describe a large number of rhythms with a couple of numbers.
  *
  * @memberof Pattern
  * @name euclid
- * @param {number} pulses the number of onsets / beats
+ * @param {number} pulses the number of onsets/beats
  * @param {number} steps the number of steps to fill
  * @returns Pattern
  * @example
@@ -76,7 +72,7 @@ export const bjork = function (ons, steps) {
  * Like `euclid`, but has an additional parameter for 'rotating' the resulting sequence.
  * @memberof Pattern
  * @name euclidRot
- * @param {number} pulses the number of onsets / beats
+ * @param {number} pulses the number of onsets/beats
  * @param {number} steps the number of steps to fill
  * @param {number} rotation offset in steps
  * @returns Pattern
@@ -86,13 +82,13 @@ export const bjork = function (ons, steps) {
  */
 
 /**
- * @example // A thirteenth century Persian rhythm called Khafif-e-ramal.
+ * @example // A thirteenth-century Persian rhythm called Khafif-e-ramal.
  * note("c3").euclid(2,5)
  * @example // The archetypal pattern of the Cumbia from Colombia, as well as a Calypso rhythm from Trinidad.
  * note("c3").euclid(3,4)
  * @example // Another thirteenth century Persian rhythm by the name of Khafif-e-ramal, as well as a Rumanian folk-dance rhythm.
  * note("c3").euclidRot(3,5,2)
- * @example // A Ruchenitza rhythm used in a Bulgarian folk-dance.
+ * @example // A Ruchenitza rhythm used in a Bulgarian folk dance.
  * note("c3").euclid(3,7)
  * @example // The Cuban tresillo pattern.
  * note("c3").euclid(3,8)
@@ -151,8 +147,10 @@ export const { euclidrot, euclidRot } = register(['euclidrot', 'euclidRot'], fun
  * so there will be no gaps.
  * @name euclidLegato
  * @memberof Pattern
- * @param {number} pulses the number of onsets / beats
+ * @param {number} pulses the number of onsets/beats
  * @param {number} steps the number of steps to fill
+ * @param rotation offset in steps
+ * @param pat
  * @example
  * note("c3").euclidLegato(3,8)
  */
@@ -161,13 +159,13 @@ const _euclidLegato = function (pulses, steps, rotation, pat) {
   if (pulses < 1) {
     return silence;
   }
-  const bin_pat = _euclidRot(pulses, steps, rotation);
+  const bin_pat = _euclidRot(pulses, steps, 0);
   const gapless = bin_pat
     .join('')
     .split('1')
     .slice(1)
     .map((s) => [s.length + 1, true]);
-  return pat.struct(timeCat(...gapless));
+  return pat.struct(timeCat(...gapless)).late(rotation / steps);
 };
 
 export const euclidLegato = register(['euclidLegato'], function (pulses, steps, pat) {
@@ -180,7 +178,7 @@ export const euclidLegato = register(['euclidLegato'], function (pulses, steps,
  * the resulting sequence
  * @name euclidLegatoRot
  * @memberof Pattern
- * @param {number} pulses the number of onsets / beats
+ * @param {number} pulses the number of onsets/beats
  * @param {number} steps the number of steps to fill
  * @param {number} rotation offset in steps
  * @example

packages/core/test/euclid.test.js

@@ -0,0 +1,89 @@
+import { bjork } from '../euclid.mjs';
+import { describe, expect, it } from 'vitest';
+import { fastcat } from '../pattern.mjs';
+
+describe('bjork', () => {
+  it('should apply bjorklund to ons and steps', () => {
+    expect(bjork(3, 8)).toStrictEqual([1, 0, 0, 1, 0, 0, 1, 0]);
+    expect(bjork(-3, 8)).toStrictEqual([0, 1, 1, 0, 1, 1, 0, 1]);
+    expect(bjork(8, 8)).toStrictEqual([1, 1, 1, 1, 1, 1, 1, 1]);
+    expect(bjork(-8, 8)).toStrictEqual([0, 0, 0, 0, 0, 0, 0, 0]);
+    expect(bjork(5, 8)).toStrictEqual([1, 0, 1, 1, 0, 1, 1, 0]);
+  });
+});
+
+describe('euclid', () => {
+  it('Can create euclid', () => {
+    expect(
+      fastcat('a')
+        .euclid(3, 8)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/8: a', '3/8 → 1/2: a', '3/4 → 7/8: a']);
+    expect(
+      fastcat('a')
+        .euclid(5, 8)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/8: a', '1/4 → 3/8: a', '3/8 → 1/2: a', '5/8 → 3/4: a', '3/4 → 7/8: a']);
+  });
+});
+
+describe('euclidRot', () => {
+  it('Can create euclidRot', () => {
+    expect(
+      fastcat('a')
+        .euclidRot(3, 8, 2)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/8: a', '1/4 → 3/8: a', '5/8 → 3/4: a']);
+    expect(
+      fastcat('a')
+        .euclidRot(5, 8, 2)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/8: a', '1/4 → 3/8: a', '1/2 → 5/8: a', '5/8 → 3/4: a', '7/8 → 1/1: a']);
+  });
+});
+
+describe('euclidLegato', () => {
+  it('Can create euclidLegato', () => {
+    expect(
+      fastcat('a')
+        .euclidLegato(3, 8)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 3/8: a', '3/8 → 3/4: a', '3/4 → 1/1: a']);
+    expect(
+      fastcat('a')
+        .euclidLegato(5, 8)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/4: a', '1/4 → 3/8: a', '3/8 → 5/8: a', '5/8 → 3/4: a', '3/4 → 1/1: a']);
+  });
+});
+
+describe('euclidLegatoRot', () => {
+  it('Can create euclidLegatoRot', () => {
+    expect(
+      fastcat('a')
+        .euclidLegatoRot(3, 8, 2)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/4: a', '1/4 → 5/8: a', '5/8 → 1/1: a']);
+    expect(
+      fastcat('a')
+        .euclidLegatoRot(5, 8, 2)
+        .firstCycle()
+        .sort((a, b) => a.part.begin.sub(b.part.begin))
+        .map((a) => a.showWhole(true)),
+    ).toStrictEqual(['0/1 → 1/4: a', '1/4 → 1/2: a', '1/2 → 5/8: a', '5/8 → 7/8: a', '7/8 → 1/1: a']);
+  });
+});

packages/core/test/util.test.mjs

@@ -6,21 +6,25 @@ This program is free software: you can redistribute it and/or modify it under th
 
 import { pure } from '../pattern.mjs';
 import {
-  isNote,
-  tokenizeNote,
-  noteToMidi,
-  midiToFreq,
-  freqToMidi,
   _mod,
   compose,
+  flatten,
+  fractionalArgs,
+  freqToMidi,
   getFrequency,
   getPlayableNoteValue,
-  parseNumeral,
-  parseFractional,
+  isNote,
+  midiToFreq,
+  noteToMidi,
   numeralArgs,
-  fractionalArgs,
+  parseFractional,
+  parseNumeral,
+  rotate,
+  splitAt,
+  tokenizeNote,
+  zipWith,
 } from '../util.mjs';
-import { describe, it, expect } from 'vitest';
+import { describe, expect, it } from 'vitest';
 
 describe('isNote', () => {
   it('should recognize notes without accidentals', () => {
@@ -233,3 +237,46 @@ describe('fractionalArgs', () => {
     expect(add('q', 2)).toBe(2.25);
   });
 });
+
+describe('rotate', () => {
+  it('should rotate array to the left', () => {
+    expect(rotate([0, 1, 2, 3], 2)).toStrictEqual([2, 3, 0, 1]);
+    expect(rotate([0, 1, 2, 3], 0)).toStrictEqual([0, 1, 2, 3]);
+    expect(rotate([0, 1, 2, 3], -3)).toStrictEqual([1, 2, 3, 0]);
+    expect(rotate([0, 1, 2, 3], 3)).toStrictEqual([3, 0, 1, 2]);
+    expect(rotate([0], 3)).toStrictEqual([0]);
+    expect(rotate([], 3)).toStrictEqual([]);
+  });
+});
+
+describe('flatten', () => {
+  it('should flatten array by one level', () => {
+    expect(flatten([0, 1, 2, 3])).toStrictEqual([0, 1, 2, 3]);
+    expect(flatten([0, 1, [2, 3]])).toStrictEqual([0, 1, 2, 3]);
+    expect(flatten([0, [1, [2, 3]]])).toStrictEqual([0, 1, [2, 3]]);
+    expect(flatten([0])).toStrictEqual([0]);
+    expect(flatten([])).toStrictEqual([]);
+  });
+});
+
+describe('splitAt', () => {
+  it('should split array into two', () => {
+    expect(splitAt(2, [0, 1, 2, 3])).toStrictEqual([
+      [0, 1],
+      [2, 3],
+    ]);
+    expect(splitAt(0, [0, 1, 2, 3])).toStrictEqual([[], [0, 1, 2, 3]]);
+    expect(splitAt(-3, [0, 1, 2, 3])).toStrictEqual([[0], [1, 2, 3]]);
+    expect(splitAt(3, [0, 1, 2, 3])).toStrictEqual([[0, 1, 2], [3]]);
+  });
+});
+
+describe('zipWith', () => {
+  it('should use the function to combine the two arrays element-wise', () => {
+    expect(zipWith((a, b) => a + b, [0, 1, 2, 3], [0, 1, 2, 3])).toStrictEqual([0, 2, 4, 6]);
+    expect(zipWith((a, b) => a + b, [0, 1, 2, 3], [0, 1, 2])).toStrictEqual([0, 2, 4, NaN]);
+    expect(zipWith((a, b) => a + b, [0, 1, 2], [0, 1, 2, 3])).toStrictEqual([0, 2, 4]);
+    expect(zipWith((a) => a, [0, 1, 2], [1, 2, 3, 0])).toStrictEqual([0, 1, 2]);
+    expect(zipWith((a, b) => b, [0, 1, 2], [1, 2, 3, 0])).toStrictEqual([1, 2, 3]);
+  });
+});

packages/core/util.mjs

@@ -162,6 +162,7 @@ export const compose = (...funcs) => pipe(...funcs.reverse());
 // Removes 'None' values from given list
 export const removeUndefineds = (xs) => xs.filter((x) => x != undefined);
 
+// flattens by one level
 export const flatten = (arr) => [].concat(...arr);
 
 export const id = (a) => a;
@@ -237,6 +238,7 @@ export const splitAt = function (index, value) {
   return [value.slice(0, index), value.slice(index)];
 };
 
+// Uses the function f to combine the arrays xs, ys element-wise
 export const zipWith = (f, xs, ys) => xs.map((n, i) => f(n, ys[i]));
 
 export const pairs = function (xs) {