How to parallelize d3.js or cubism.js

Question

I'm following the examples on http://adambom.github.io/parallel.js/

Example:

var p = new Parallel([0, 1, 2, 3, 4, 5, 6]), 
        log = function () { console.log(arguments); };

function fib(n) {
  return n < 2 ? 1 : fib(n - 1) + fib(n - 2);
};

p.map(fib).then(log)

Works beautifully, now I want to apply the same concept on d3 objects.

I have a for loop that loops through a list of names:

for name in names by 1
  // set some stuff
  context = [....]
  metrics = [....]

  d3.select("#"+name)
    .selectAll(".horizon")
    .data(metrics).enter()
    .insert("div", ".bottom")
    .attr("class", "horizon")
    .call context.horizon()

If I put the the content of the for loop in the function fib content it complains about "undefined d3 variable" ... but I feel like I'm missing the concept.

Answer 1

You can't parallelize the chain. There's nothing special about d3 here - when you chain calls, i.e. foo(a).bar(b).foobar(c) it means that foo() returns an object with method bar() which in turn returns object with method foobar(). This essentially means that you can't run foo() and bar() in parallel, because the latter requires result from the former.