working out some harmony logic

js/harmonyUtil.js

@@ -0,0 +1,64 @@
+import { extractPitchset } from "./toneGeneration.js";
+
+// interval definitions:
+const intervals = {
+    0: "unison",
+    1: "minor second",
+    2: "major second",
+    3: "minor third",
+    4: "major third",
+    5: "perfect fourth",
+    6: "tritone"
+    // all intervals beyond this invert to one of the previous intervals
+}
+
+// helper functions
+const transposePitches = (pitchNames, interval) => {
+    let transposed = [];
+    pitchNames.forEach(pitch => transposed.push((pitch + interval) % 12));
+    return transposed;
+}
+
+const findVector = (pitches) => {
+    let sorted = pitches.sort((x,y) => x - y);
+    // sorted = sorted.filter((num, idx) => {
+    //     return sorted.indexOf(num) === idx;
+    // });
+
+    // finds each interval and logs it as a duple
+    let intervalClasses = [];
+    for (let i = 0; i < sorted.length; i++) {
+        let j = i+1;
+
+        // does not allow out of range values in the proceeding loop
+        if (j >= sorted.length) {
+            break;
+        }
+
+        do {
+            let thing = (sorted[j] - sorted[i]) % 6
+            if (!(intervalClasses.includes(thing))) {
+                intervalClasses.push(thing);
+            }
+            j++;
+        } while (j < sorted.length);
+    }
+
+    intervalClasses = intervalClasses.sort((x,y) => x-y);
+    return intervalClasses;
+}
+
+// analysis
+let dMajor = extractPitchset(["D", "F#", "A", "D"]);
+const eMajor = transposePitches(dMajor, 2);
+console.log(eMajor);
+console.log('');
+
+let dMajVector = findVector(dMajor);
+console.log(dMajVector);
+
+let complexVector = findVector([0,3,4,7,8,11]);
+console.log(complexVector);
+
+let splitThird = findVector([0,3,4,7]);
+console.log(splitThird);

js/toneGeneration.js

@@ -28,7 +28,7 @@ export const extractPitchset = (pitches) => {
     pitchset.sort((a,b) => a < b);
     console.log(pitchset);
 
-    // 
+    return pitchset;
 }
 
 // no tritones

package.json

@@ -1,5 +1,6 @@
 {
   "name": "tone",
+  "type": "module",
   "version": "1.0.0",
   "description": "",
   "main": "app.js",