Function tweenValue

external/.d3.js:4415–4426

(transition, name, value)

}

function tweenValue(transition, name, value) {
  var id = transition._id;

  transition.each(function() {
    var schedule = set(this, id);
    (schedule.value || (schedule.value = {}))[name] = value.apply(this, arguments);
  });

  return function(node) {
    return get(node, id).value[name];
  };
}

function interpolate$1(a, b) {
  var c;