Chart.js在条形图上压缩垂直轴 [英] Chart.js compress vertical axis on barchart

问题描述

我有一个数据集，其中的最后一个值始终很高.这会导致我的条形图出现问题；如果不将它们悬停在几乎所有其他值上，就很难感觉到.

I have a dataset in which the last value is always very high. This causes an issue with my bar chart; almost all the other values are hard to get a feeling for without hovering over them.

以下是屏幕截图:

这就是我要实现的目标；

This is what I am trying to achieve;

所以我的问题；可以在香草Chart.js中实现此功能，还是需要一个插件?如果是这样;是否有现有的插件，或者我需要自己编写一个插件?

So my question; is this possible within vanilla Chart.js or do I need a plugin? And if so; is there an existing plugin or do I need to write one myself?

我也愿意为最初的问题提供替代解决方案.

I am also open for alternative solutions to the initial problem.

我已经在互联网上寻找了类似的东西，但不幸的是运气不佳.

I've looked all over the internet for something like this but unfortunately without much luck.

推荐答案

您可以使用对数类型 yAxis

默认值:线性

https://www.chartjs.org/docs/latest/axes/cartesian/logarithmic.html

var ctx = document.getElementById('myChart');

var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June"],
    datasets: [{
      label: "Series 1",
      backgroundColor: "rgba(255,99,132,0.2)",
      borderColor: "rgba(255,99,132,1)",
      borderWidth: 2,
      hoverBackgroundColor: "rgba(255,99,132,0.4)",
      hoverBorderColor: "rgba(255,99,132,1)",
      data: [65, 59, 43, 81, 56, 950],
    }]
  },
  options: {
    scales: {
      yAxes: [{
        type: 'logarithmic',
        ticks: {
          callback: function(tick, index, ticks) {
            return tick.toLocaleString();
          }
        }
      }]
    }
  }
});

<script src="https://cdn.jsdelivr.net/npm/chart.js@2.8.0"></script>
<canvas id="myChart" width="400" height="200"></canvas>

优化的价格变动

50 * (Math.floor(i / 50)), // lower 50
50 * (Math.ceil(i / 50)) // higer 50

var ctx = document.getElementById('myChart');

var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June"],
    datasets: [{
      label: "Series 1",
      backgroundColor: "rgba(255,99,132,0.2)",
      borderColor: "rgba(255,99,132,1)",
      borderWidth: 2,
      hoverBackgroundColor: "rgba(255,99,132,0.4)",
      hoverBorderColor: "rgba(255,99,132,1)",
      data: [65, 59, 43, 81, 56, 950],
    }]
  },
  options: {
    scales: {
      yAxes: [{
        type: 'logarithmic',
        ticks: {
          callback: function(tick, index, ticks) {
            return tick.toLocaleString();
          }
        },
        afterBuildTicks: function(pckBarChart) {
          pckBarChart.ticks = pckBarChart.chart.data.datasets[0].data.flatMap(i => [
            50 * (Math.floor(i / 50)), // lower 50
            50 * (Math.ceil(i / 50)) // higer 50
          ])
        }
      }]
    }
  }
});

<script src="https://cdn.jsdelivr.net/npm/chart.js@2.8.0"></script>
<canvas id="myChart" width="400" height="200"></canvas>

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