Remember that map reduce reduces a dataset by keys of a particular dimension. For example lets use a crossfilter instance with records: [ { name: “Gates”, age: 57, worth: 72000000000, gender: “m” }, { name: “Buffet”, age: 59, worth: 58000000000, gender: “m” }, { name: “Winfrey”, age: 83, worth: 2900000000, gender: “f” }, { name: … Read more
use a comprehension for d, i in flights console.log d, i The code above translates to var d, i, _i, _len; for (i = _i = 0, _len = flights.length; _i < _len; i = ++_i) { d = flights[i]; console.log(d, i); } so you can see d and i are what you want them … Read more
Solved it myself, here’s fiddle with working code http://jsfiddle.net/uhXf5/6/ Here’s code in case someone will came across similar problem: function reduceAdd(p, v) { v.tags.forEach (function(val, idx) { p[val] = (p[val] || 0) + 1; //increment counts }); return p; } function reduceRemove(p, v) { v.tags.forEach (function(val, idx) { p[val] = (p[val] || 0) – 1; … Read more