allow frequency modulation in sine() method

tmhglnd · Mar 19, 2021 · 5e9d8a0 · 5e9d8a0
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diff --git a/docs/generative-methods.md b/docs/generative-methods.md
@@ -78,34 +78,49 @@ Gen.spreadInclusive(5, 3, 12);
 Gen.spreadInclusive(5, 12, 3);
 //=> [ 12, 9, 7, 5, 3 ] 
 
-// generate an array of 9 floats between -1 - 1 (inclusive)
-Gen.spreadInclusiveFloat(9, -1, 1); 
-//=> [ -1, -0.75, -0.5, -0.25, 0, 0.25, 0.5, 0.75, 1 ]
+// generate an array of 5 floats (inclusive)
+Gen.spreadInclusiveFloat(5);
+//=> [ 0, 0.25, 0.5, 0.75, 1 ] 
 // Alternative: Gen.spreadIncF()
 
 ```
 
 ## spreadExp
 
-Similar to spread and spreadFloat but with an optional exponent as 4th argument
+Similar to spread and spreadFloat but with an optional exponent as 4th argument.
 
 **arguments**
 - {Int+} -> Length of array
 - {Number} -> Low value (optional, default=0)
 - {Number} -> High value (exclusive, optional, default=length)
 - {Number} -> Exponent (optional, default=1)
 
-## spreadInclusiveExp
+```js
+Gen.spreadExp(10, 0, 10, 2);
+//=> [
+//   0, 0, 0, 0, 1,
+//   2, 3, 4, 6, 8
+// ] 
+```
 
-Similar to spreadInclusive and spreadInclusiveFloat but with an optional exponent as 4th argument
+## spreadInclusiveExp
 
+Similar to spreadInclusive and spreadInclusiveFloat but with an optional exponent as 4th argument.
 
 **arguments**
 - {Int+} -> Length of array
 - {Number} -> Low value (optional)
 - {Number} -> High value (inclusive, optional)
 - {Number} -> Exponent (optional, default=1)
 
+```js
+Gen.spreadInclusiveExp(10, 0, 10, 2);
+//=> [
+//   0, 0, 0, 1,  1,
+//   3, 4, 6, 7, 10
+// ] 
+```
+
 ## fill
 
 Fill an array with values. Arguments are in pairs. Every pair consists of `<value, amount>` The value is repeated n-amount of times in the array.
@@ -220,6 +235,19 @@ Gen.cosineFloat(8);
 //       -0.60 ┤    ╰╮    ╭╯    
 //       -1.00 ┤     ╰────╯      
 
+// frequency modulation of the period argument with another array
+Gen.sineFloat(40, Gen.sineFloat(40, 4, 1, 5));
+//=>  1.00 ┤ ╭╮  ╭──╮           ╭╮   ╭╮  ╭─╮        
+//    0.80 ┤ │╰╮╭╯  │ ╭╮  ╭╮    ││   ││ ╭╯ │        
+//    0.60 ┤╭╯ ││   ╰╮││  ││    ││   ││ │  │        
+//    0.40 ┤│  ╰╯    │││  ││    ││   ││ │  │        
+//    0.20 ┤│        ││╰╮╭╯│╭╮  ││   ││ │  │╭╮   ╭╮ 
+//    0.00 ┼╯        ││ ││ ││╰╮╭╯│ ╭╮││ │  │││  ╭╯│ 
+//   -0.20 ┤         ││ ││ ││ ││ │ ││││ │  │││  │ │ 
+//   -0.40 ┤         ││ ││ ││ ││ │ ││││ │  ╰╯╰╮ │ │ 
+//   -0.60 ┤         ││ ╰╯ ││ ││ │ ││││ │     │ │ │ 
+//   -0.80 ┤         ││    ││ ╰╯ │ │╰╯│ │     ╰─╯ │ 
+//   -1.00 ┤         ╰╯    ╰╯    ╰─╯  ╰─╯         ╰  
 ```
 
 <iframe src="https://editor.p5js.org/tmhglnd/embed/CFOwE1yhW" width="100%" height="250px" frameBorder="0" scrolling="no"></iframe>
diff --git a/src/gen-basic.js b/src/gen-basic.js
@@ -181,10 +181,10 @@ exports.spreadInclusiveExp = spreadInclusiveExp;
 // @return {Array}
 // 
 function fill(...args){
-	// when no arguments return array of 0
-	if (!args.length){ return [0]; }
 	// when arguments uneven strip last argument
 	if (args.length % 2){ args.pop(); }
+	// when no arguments return array of 0
+	if (!args.length){ return [0]; }
 
 	let len = args.length/2;
 	let arr = [];
@@ -211,6 +211,8 @@ exports.fill = fill;
 function sineFloat(len=1, periods=1, lo, hi, phase=0){
 	if (lo === undefined){ lo = -1; hi = 1; }
 	else if (hi === undefined){ hi = lo, lo = 0; }
+	// make periods array
+	periods = Array.isArray(periods)? periods : [periods];
 	// if no range specified
 	// if (lo === undefined){ lo = -1; hi = 1; }
 	// swap if lo > hi
@@ -220,9 +222,12 @@ function sineFloat(len=1, periods=1, lo, hi, phase=0){
 	len = Math.max(1, len);
 	let arr = [];
 
-	let a = Math.PI * 2.0 * periods / len;
+	let twoPI = Math.PI * 2.0;
+	// let a = Math.PI * 2.0 * periods / len;
 	let p = Math.PI * phase * 2.0;
 	for (let i=0; i<len; i++){
+		// arr[i] = Math.sin(a * i + p);
+		let a = twoPI * periods[i % periods.length] / len;
 		arr[i] = Math.sin(a * i + p);
 	}
 	return Util.map(arr, -1, 1, lo, hi);
@@ -265,3 +270,4 @@ function cosine(len=1, periods=1, lo=12, hi, phase=0){
 	return arr.map(v => Math.trunc(v));
 }
 exports.cosine = cosine;
+
diff --git a/test/serialism.test.js b/test/serialism.test.js
@@ -123,17 +123,15 @@ function testGen(){
 	test("Gen.spreadInclusiveFloatExp(12, 0, 10, 0.5)");
 
 	// test("Gen.fill()");
-	// test("Gen.fill(10, 2, 15, 3, 20, 4)");
+	test("Gen.fill(10, 2, 15, 3, 20, 4)");
+	test("Gen.fill([10, 20], 2, 15, 3, 20, 4)");
+	test("Gen.fill([10, 20, 2, 15, 3, 20, 4])");
+
+	test("Util.plot(Gen.sineFloat(40, Gen.sineFloat(40, 4, 1, 5)), {log: false, height: 10})");
 
-	// test("Util.plot(Gen.sineFloat(16), {log: false, height: 5, data: true})");
-	// test("Gen.sineFloat(10, 1, -1, 1, 0.5)");
-	// // test("Gen.sin(8)");
 	// test("Util.plot(Gen.cosineFloat(16), {log: false, height: 5, data: true})");
-	// // test("Gen.cos(8)");
 
 	// test("Util.plot(Gen.sine(10), {log: false})");
-	// test("Gen.sine(12, 1, -1, 1)");
-	// test("Util.plot(Gen.sine(11, 4, 0, 7), {log: false})");
 
 	// test("Util.plot(Gen.cosine(7, 1.5), {log: false})");
 }