CODEWITHSUNDEEP
javascriptarraysd3.js
Laguland
Laguland

Reputation: 65

How can I sum an array with D3?

I'm struggling with summing an array. I don't have any error so I am not sure how to make it work.

my data passed to the function look like this:

{Region:'' ,freq:{yesVote:0, noVote:0}}

I try to sum it like this:

    // compute pie slice angles
    var pie = d3.pie().sort(null).value(function (d) {
        var yesTotal;
        var noTotal;
        console.log(d);

        yesTotal = d3.sum(d, function(v){
            console.log(v.freq);
           return v.freq.yesVote;
        });

        noTotal = d3.sum(d, function(v){
           return v.freq.noVote;
        });

        console.log(yesTotal);
        console.log(noTotal);

        return [yesTotal,noTotal];
    });

Sum function returns 0 and log function inside sum functions doesn't appear in the console (first log print data properly) so I assume there is something wrong with data passed to the sum function. Can you please explain me where I do mistake?

EDIT

printed data:

enter image description here

Upvotes: 1

Views: 2172

Answers (1)

Archdoog
Archdoog

Reputation: 890

If this is what console.log(d) is producing: 

{Region:'' ,freq:{yesVote:0, noVote:0}}

then yes, you're not passing the correct data. You're only passing an object with a single value set. d3.sum() should operate on the full array of data. Example:

var data = [
  {Region: 'A' ,freq: {yesVote:1, noVote:10}},
  {Region: 'B' ,freq: {yesVote:2, noVote:11}},
  {Region: 'C' ,freq: {yesVote:3, noVote:12}}
];

yesTotal = d3.sum(data, function(d) {
  return d.freq.yesVote;
});

noTotal = d3.sum(data, function(d) {
  return d.freq.noVote;
});

console.log(yesTotal)
6
console.log(noTotal)
33

Try moving the sum out of the pie chart value function, because inside, d is just a single row from your entire data set.

Upvotes: 5

Related Questions