How to count unique value per key with multiple values array ? / DC.js - Crossfilter - Reductio

Question

---

Hi, i need to make a barchart with these type of data set.

How to make exceptionCount for each productIDs at each days like this :

For day 2011-11-14 count 3 occurs (001, 004, 005), etc...

Tried many methods, like reductio, unique count, but didn't find solution.

productIDs's array often change because of regular import of new data.

data([
  {date: "2011-11-14", quantity: 2, total: 190, tip: 100, type: "tab", productIDs:["001"]},
  {date: "2011-11-14", quantity: 2, total: 190, tip: 100, type: "tab", productIDs:["001", "005"]},
  {date: "2011-11-14", quantity: 1, total: 300, tip: 200, type: "visa", productIDs:["004" ,"005"]},
  {date: "2011-11-15", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["001", "002"]},
  {date: "2011-11-15", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["005"]},
  {date: "2011-11-15", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["001", "004" ,"005"]},
  {date: "2011-11-16", quantity: 1, total: 100, tip: 0, type: "cash", productIDs:["001", "002", "003", "004" ,"005"]},
  {date: "2011-11-16", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["001"]},
  {date: "2011-11-16", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["004" ,"005"]},
  {date: "2011-11-17", quantity: 2, total: 90, tip: 0, type: "tab", productIDs:["001", "002", "004" ,"005"]},
  {date: "2011-11-17", quantity: 2, total: 200, tip: 0, type: "cash", productIDs:["002"]},
  {date: "2011-11-17", quantity: 1, total: 200, tip: 100, type: "visa", productIDs:["004"]}
])

            var dim = ndx.dimension(function(d) { return d.date; });
            var pgroup = dim.group();

            var reducer = reductio()

                .exception(function(d) { return d.productIDs;}).exceptionCount(true);

                reducer(pgroup);
                pgroup.top([Infinity]);

            Barchart
                .dimension(dim)
                .group(pgroup)
                .xUnits(dc.units.ordinal)
                .x(d3.scale.ordinal())      
                .elasticY(true)
                .brushOn(true)
                .valueAccessor(function(p) { 
                 return p.value.exceptionCount;});

Thanks for your help

Answer 1

I don't know if reductio supports this; I guess it would be some sort of exception-array operation in that vocabulary.

Here is one way to do it with straight crossfilter and dc.js:

var dim = ndx.dimension(function(d) { return d.date; });
var pgroup = dim.group().reduce(
    function(p, v) { // add
        v.productIDs.forEach(x => p[x] = (p[x] || 0) + 1);
        return p;
    },
    function(p, v) { // remove
        v.productIDs.forEach(x => { if(--p[x] === 0) delete p[x] });
        return p;
    },
    function() { // init
        return {};
    }
);

Barchart
    .valueAccessor(p => Object.keys(p.value).length)

demo fiddle