时间图表chart.js

2022-01-22 00:00:00 charts javascript chart.js

我正在学习如何使用 chart.js，我想要一个显示一天中不同时间(x 轴)的随机值的图表，格式为h?h:mm".

在 x 轴上，我想要一小时的固定步长，从上午 12 点 (0:00) 开始，到上午 8 点 (8:00) 结束.

而数据，例如 (x = 4:45, y = 67) 在 te 对应的 x tick (3/4 between 4:00 and 5:00)

我尝试了以下方法:

var cfg = {类型:'线'，数据: {标签:['00:00'、'01:35'、'02:20'、'03:05'、'04:07'、'04:57'、'05:25'、'06:08', '07:10'],数据集:[{数据: [randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),randomScalingFactor(18, 45),随机缩放因子(18, 45)],标签:改进的 ETA"，边框颜色:#e67e22"，边框宽度:2，填充:假，线张力:0}]},选项: {响应式:真实，保持纵横比:假，标题: {显示:真，text: '改进的 ETA',字体大小:14，fontFamily: 'Arial',字体颜色:'#000'},传奇: {显示:假},秤:{x轴:[{滴答声:{填充:12},网格线: {颜色:'rgba(0, 0, 0, 0.06)',zeroLineColor: 'rgba(0, 0, 0, 0.06)',drawTicks: 假}}],y轴:[{滴答声:{建议Min: 0,建议最大:80，填充:12},刻度标签:{显示:真，标签字符串:'分钟'},网格线: {颜色:'rgba(0, 0, 0, 0.06)',zeroLineColor: 'rgba(0, 0, 0, 0.06)',drawTicks: 假}}]}}};window.onload = 函数(){var ctx = document.getElementById('foo').getContext('2d');window.myLine = new Chart(ctx, cfg);};

<div style="width: 600px; height: 400px;"><canvas id="foo"></canvas></div>

但这不是我想要的，因为 X 轴刻度采用标签的值(x 数据).更糟糕的是，刻度之间的间隔总是相同的(例如，从 10:30 到 10:40 与 8:00 到 9:00 之间的间隔相同).

PD:由于时间图，我还阅读了有关使用 moment.js chart.js 包的信息:https://www.chartjs.org/samples/latest/scales/time/line.html

解决方案

首先你应该省略 labels 但将你的数据定义为个别点，其中每个元素都有一个t和一个y 属性.

数据:[{ t: '4:45', y: 67 },{ t: '6:12', y: 45 },{ t: '7:33', y: 56 },],

有了以上数据，xAxes.time 选项必须定义如下:

时间:{解析器:'H:mm'，单位:'小时'，步长:1，显示格式:{小时:'H:mm'},tooltipFormat: 'H:mm'},

您还可以定义 xAxis.ticks 选项如下:

记号:{分钟:'0:00'，最大值:'8:00'}

<块引用>

您已经注意到，Chart.js 在内部使用 Moment.js 来实现时间轴.因此，您应该使用捆绑版本 Chart.js 在单个文件中包含 Moment.js.

请看看下面的可运行代码，看看它是如何工作的.

new Chart('myChart', {类型:'线'，数据: {数据集:[{标签:我的数据集"，数据: [{ t: '4:45', y: 67 },{ t: '6:12', y: 45 },{ t: '7:33', y: 56 },],边框颜色:'蓝色'，填充:'假'，}]},选项: {秤:{y轴:[{滴答声:{beginAtZero: 真}}],x轴:[{类型:'时间'，时间: {解析器:'H:mm'，单位:'小时'，步长:1，显示格式:{小时:'H:mm'},tooltipFormat: 'H:mm'},滴答声:{分钟:'0:00'，最大值:'8:00'}}]}}});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.bundle.min.js"></script><canvas id="myChart" height="90"></canvas>

I'm learning how to use chart.js and I want a graph that displays random values in different hours of the day (x axis) with format "h?h:mm".

In the x axis I want a fixed step of one hour, starting at 12 AM (0:00) and ending at 8 AM (8:00).

And the data, for example (x = 4:45, y = 67) in te corresponding x tick (3/4 between 4:00 and 5:00)

I tried the following:

var cfg = {
  type: 'line',
  data: {
    labels: ['00:00', '01:35', '02:20', '03:05', '04:07', '04:57', '05:25', '06:08', '07:10'],
    datasets: [{
      data: [
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45),
        randomScalingFactor(18, 45)
      ],
      label: "Improved ETA",
      borderColor: "#e67e22",
      borderWidth: 2,
      fill: false,
      lineTension: 0
    }]
  },
  options: {
    responsive: true,
    maintainAspectRatio: false,
    title: {
      display: true,
      text: 'Improved ETA',
      fontSize: 14,
      fontFamily: 'Arial',
      fontColor: '#000'
    },
    legend: {
      display: false
    },
    scales: {
      xAxes: [{
        ticks: {
          padding: 12
        },
        gridLines: {
          color: 'rgba(0, 0, 0, 0.06)',
          zeroLineColor: 'rgba(0, 0, 0, 0.06)',
          drawTicks: false
        }
      }],
      yAxes: [{
        ticks: {
          suggestedMin: 0,
          suggestedMax: 80,
          padding: 12
        },
        scaleLabel: {
          display: true,
          labelString: 'mins'
        },
        gridLines: {
          color: 'rgba(0, 0, 0, 0.06)',
          zeroLineColor: 'rgba(0, 0, 0, 0.06)',
          drawTicks: false
        }
      }]
    }
  }
};

window.onload = function() {
  var ctx = document.getElementById('foo').getContext('2d');
  window.myLine = new Chart(ctx, cfg);
};

<div style="width: 600px; height: 400px;">
  <canvas id="foo"></canvas>
</div>

But is not what I want, because the X axis ticks take the values of the labels (x data). And what is even worse the space between ticks is always the same (e.g from 10:30 to 10:40 there is the same space as 8:00 to 9:00).

PD: I also have read about using moment.js chart.js bundle because of the time graph: https://www.chartjs.org/samples/latest/scales/time/line.html

解决方案

First you should omit labels but define your data as individual points, where each element has a t and an y property.

data: [
  { t: '4:45', y: 67 },
  { t: '6:12', y: 45 },
  { t: '7:33', y: 56 },
],

With above data, xAxes.time option will have to be defined as follows:

time: {
  parser: 'H:mm',
  unit: 'hour',
  stepSize: 1,
  displayFormats: {
    hour: 'H:mm'
  },
  tooltipFormat: 'H:mm'
},

Further you can define the xAxis.ticks option as follows:

ticks: {
  min: '0:00', 
  max: '8:00' 
}

As you already noticed, Chart.js internally uses Moment.js for the functionality of the time axis. Therefore you should use the bundled version of Chart.js that includes Moment.js in a single file.

Please take a look at the runnable code below and see how it works.

new Chart('myChart', {
  type: 'line',
  data: {
    datasets: [{
      label: 'My Dataset',      
      data: [
        { t: '4:45', y: 67 },
        { t: '6:12', y: 45 },
        { t: '7:33', y: 56 },
      ],
      borderColor: 'blue',
      fill: 'false',
    }]
  },
  options: {
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }],
      xAxes: [{
        type: 'time',
        time: {
          parser: 'H:mm',
          unit: 'hour',
          stepSize: 1,
          displayFormats: {
            hour: 'H:mm'
          },
          tooltipFormat: 'H:mm'
        },
        ticks: {
          min: '0:00', 
          max: '8:00' 
        }
      }]      
    }
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.bundle.min.js"></script>
<canvas id="myChart" height="90"></canvas>

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