如何配置 flot 以在 y 轴上的零点绘制缺失的时间序列? [英] How to configure flot to draw missing time series on y-axis at point zero?

问题描述

我正在使用flot(

I'm using flot (flot on github) to draw a graph with the following time series data:

[
    [1357171200000, 1],
    [1357344000000, 1],
    [1357430400000, 2],
    [1357516800000, 2],
    [1357689600000, 3],
    [1357776000000, 1]
]

As you can see there are some points in the graph wich show the sales for the given day. My json response doesn't contain sales count / data for days where no sale has happened. For example the 04th of January. How can i configure flot to draw the missing days on y-axis at point zero (because there are no sales)? As you can see in the image flot does connect the points so there are no zero points in the graph.

解决方案

Here's a solution that creates a new Array adding in missing days and setting their values to zero:

/* create and return new array padding missing days*/
function newDataArray(data) {
  var startDay = data[0][0],
    newData = [data[0]];

  for (i = 1; i < data.length; i++) {
    var diff = dateDiff(data[i - 1][0], data[i][0]);
    var startDate = new Date(data[i - 1][0]);
    if (diff > 1) {
      for (j = 0; j < diff - 1; j++) {
        var fillDate = new Date(startDate).setDate(startDate.getDate() + (j + 1));
          newData.push([fillDate, 0]);
      }
    }
    newData.push(data[i]);
  }
  return newData;
}


/* helper function to find date differences*/
function dateDiff(d1, d2) {
  return Math.floor((d2 - d1) / (1000 * 60 * 60 * 24));
}

To use:

var data = [
  [1357171200000, 1],
  [1357344000000, 1],
  [1357430400000, 2],
  [1357516800000, 2],
  [1357689600000, 3],
  [1357776000000, 1]
];

var newData=newDataArray(data);
/* pass newData to flot*/

DEMO: http://jsfiddle.net/LK2gD/3/

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