D3.js折线图，时间在两个轴上

我想画一个折线图，x轴是日期，y轴是时间，单位是分钟和秒。

轴都很好，但当我试图绘制线图时，它没有显示我预期的。

我最终得到了沿轴的线。

这是我的js代码

/**
 * Function for sorting times
 */
function numOrdA(a, b){ return (a[1]-b[1]); }
/**
 * Array of timestamps and times in seconds
 */
var data = [
    [1395237411, 130],
    [1395950916, 90],
    [1397557328, 95],
    [1398353666, 87]
];
/**
 * Sort the data by the time in seconds
 */
data.sort(numOrdA);
var width = 700,
    height = 400,
    padding = 100;
/**
 * Create an svg container
 */
var vis = d3.select("body").
    append("svg:svg")
    .attr("width", width)
    .attr("height", height);
/**
 * Create min and max dates for x axis
 */
var mindate = new Date,
    maxdate = new Date;
mindate.setTime(data[0][0] * 1000);
maxdate.setTime(data[data.length - 1][0] * 1000);
/**
 * Create min and max times for y axis
 */
var mintime = new Date,
    maxtime = new Date;
mintime.setTime(data[0][1] * 1000);
maxtime.setTime(data[data.length - 1][1] * 1000);
/**
 * Create y scale using min and max times
 */
var yScale = d3.time.scale()
    .domain([mintime, maxtime])
    .range([height - padding, padding]);
/**
 * Create x scale with min and max dates
 */
var xScale = d3.time.scale()
    .domain([mindate, maxdate])
    .range([padding, width - padding * 2]);
/**
 * Create the y axis with time in minutes and seconds
 */
var yAxis = d3.svg.axis()
    .orient("left")
    .scale(yScale)
    .tickFormat(d3.time.format("%M:%S"));
/**
 * Create the x axis with a date format
 */
var xAxis = d3.svg.axis()
    .orient("bottom")
    .scale(xScale)
    .tickFormat(d3.time.format("%a %x"));
/**
 * Append y axis
 */
vis.append("g")
    .attr("transform", "translate("+padding+",0)")
    .call(yAxis);
/**
 * Append the x axis
 */
vis.append("g")
    .attr("class", "xaxis")
    .attr("transform", "translate(0," + (height - padding) + ")")
    .call(xAxis);
/**
 * Rotate the text on the x axis
 */
vis.selectAll(".xaxis text")
    .attr("transform", function(d) {
        return "translate(" + this.getBBox().height*-2 + "," + this.getBBox().height + ")rotate(-45)";
    });
/**
 * Line function to plot the times (y axis) against dates (x axis)
 */
var line = d3.svg.line()
        .x(function(d) {
            return xScale(d[1]);
        })
        .y(function(d) {
            return yScale(d[0]);
        });
/**
 * Add the path to the svg
 */
vis.append("svg:path").attr("d", line(data));

下面是jsfiddle

感谢您的帮助