map-reduce reduce

reduce = function(key, values) {
    var prices = 0.0;
    var volume = 0.0;
    var total = 0.0;
    var high = values[0].price;
    var low = values[0].price;
    var count = 0;
    values.forEach(function(value)
    {   
        prices += value.price;
        volume+= value.volume;
        total+= value.total;
        if(value.price > high)
            high = value.price;
        if(value.price < low)
            low = value.price;
        count+=1;
    });

    var result = { 
            open: values[0].price,
            close: values[values.length-1].price,
            high: high,
            low: low,
            price: prices/count,
            volume: volume,
            total: total,
            count: count,
    };
    return result;
}