使用D3获取具有最大值的对象

Question

I have an array of objects from which I can easily get a max value like this:

    var maxValue = d3.max(data, function (d, i) {
        return d.value
    });

Now, how can I get not the max value, but the object which contains this value? Is there a D3-specific way to do this?

Answer 1

No need for D3 here, the Javascript built-in .sort() is enough:

data.sort(function(a, b) { return b.value - a.value; });

After this, data will be in descending order. That is, data[0] is the element with the highest .value .

Answer 2

A crude implementation:

(function()
{
    d3.each = function(array, fn, context)
    {
        for(var i = 0, len = array.length; i < len; i++)
        {
            fn.call(context || this, array[i], i);
        }
    }
})();


var data = [{ 'value' : 1 }, { 'value' : 6 }, { 'value' : 100 }, { 'value' : 56 }, { 'value' : 21 }];


var max = null;
d3.each(data, function(d, i)
{
    if(!max || d.value > max.value)
    {
        max = d;
    }
});

console.log(max)

http://jsfiddle.net/xhVn4/

You also get a fancy (not really :) ) new d3 helper function (couldn't fnd it in the D3 API)