jremmen’s gists

jremmen / objectpluck.js

Last active December 18, 2015 22:29

js: recursive pluck for javascript objects

	function opop(obj,k) {
	for(o in obj) {
	if(o == k) {
	result = obj[o];
	delete obj[o];
	return result;
	}
	else if(typeof obj[o] == 'object' && obj[o].constructor == Object) {
	if(a = opop(obj[o], k)) return a;
	}

jremmen / mergesort.js

Created July 4, 2013 00:11

js: merge sort

	function mergesort(list) {
	if(list.length <= 1) return list;
	var l = mergesort(list.slice(0, list.length / 2));
	var r = mergesort(list.slice(list.length / 2));
	return merge(l, r);
	}

	function merge(l, r) {
	var result = [];
	while(l.length > 0 \|\| r.length > 0) {

jremmen / pointdistance.js

Created July 14, 2013 01:32

calculate distance between two points

	var Point = function(x, y) {
	this.x = x;
	this.y = y;
	};

	function getDistance(a, b) {
	return Math.sqrt(Math.pow((a.x - b.x), 2) + Math.pow((a.y - b.y), 2));
	};

jremmen / quicksort.js

Created July 22, 2013 01:03

js: quicksort

jremmen / recursiveMinMax.js

Last active December 20, 2015 08:19

js: recursive max and min with partial application

	var max = reduce(function(a, b) { return a > b; });
	var min = reduce(function(a, b) { return a < b; });

	function reduce(p) {
	return function(a) {
	function iter(a, c) {
	if(a.length === 0) return c;
	else return iter(a.slice(1), p(a[0], c) ? a[0] : c);
	}
	return iter(a.slice(1), a[0]);

jremmen / pa.js

Created November 5, 2013 22:43

js: partial application example

	calculate = function(a, f) { return a.reduce(function(x,y) { return f(x, y) }); }

	sum = function(a, b) { return a + b; }
	sub = function(a, b) { return a - b; }

	sumAll = function(a) { return calculate(a, sum); }
	subAll = function(a) { return calculate(a, sub); }

jremmen / bin2text_text2bin.js

Last active August 29, 2015 13:56

A couple of javascript one liners for easily converting text message to binary and binary messages to text.

	function text2bin(msg) { return msg.split('').map(function(x) { var b = x.charCodeAt(0).toString(2); return Array(9 - b.length).join(0) + b; }).join(''); }

	function bin2text(bin) { return bin.match(/(.{1,8})/g).map(function(x) { return String.fromCharCode(parseInt(x, 2)) }).join(''); }

jremmen / im.js

Created March 9, 2014 00:14

js: generate n x n identity matrix

function im(n) { var a = Array.apply(null, new Array(n)); return a.map(function(x, i) { return a.map(function(y, k) { return i === k ? 1 : 0; }) }) }

jremmen / mm.js

Last active May 7, 2024 01:39

js: matrix multiplication using dot product and transposition

	mmultiply = function(a,b) {
	return a.map(function(x,i) {
	return transpose(b).map(function(y,k) {
	return dotproduct(x, y)
	});
	});
	}

	dotproduct = function(a,b) {
	return a.map(function(x,i) {

jremmen / zipw.js

Last active August 29, 2015 13:57

js: zip with function, takes 2 lists/arrays and zips them by mapping function (f) over each pair

	zipw = function(a,b,f) {
	var c = a.length < b.length ? {a:a, b:b} : {a:b, b:a};
	return c.a.map(function(x,i) {
	return f(x,c.b[i]);
	});
	}
	zipw([1,2,3],[10,11,12], function(x,y) { return x + y; }); // [11,13,15]
	zipw([1,2,3],[10,11,12], function(x,y) { return x * y; }); // [10,22,36]

John Remmen jremmen