chartjs-chart-error-bars

Chart.js Error Bars

Chart.js module for charting error bars plots. This plugin extends the several char types (bar, horizontalBar, line, scatter, polarArea) with their error bar equivalent (barWithErrorBars, lineWithErrorBars, scatterWithErrorBars, polarAreaWithErrorBars).

Works only with Chart.js >= 3.0.0

Bar Chart

Horizontal Bar Chart

Line Chart

Scatterplot

Polar Area plot

Install

npm install --save chart.js chartjs-chart-error-bars

Usage

see Samples on Github

and

Styling

Several new styling keys are added to the individual chart types

Data structure

The data structure depends on the chart type. It uses the fact that chart.js is supporting scatterplot. Thus, it is already prepared for object values.

Chart types: bar and line

Chart type: bar with indexAxis: 'y'

Chart type: scatter

Chart type: polarArea

Multiple Error Bars

Multiple error bars are supported.

Styling

The styling options support different array version.

Note: as with other chart.js style options, using an array will be one value per dataset. Thus, to specify the values for different error bars, one needs to wrap it in an object with a v key having the value itself. The outer for the dataset, the inner for the error bars.

Data structure

Just use array of numbers for the corresponding data structures attributes (xMin, xMax, yMin, yMax). The error bars will be rendered in reversed order. Thus, by convention the most inner error bar is in the first place.

e.g.

{
  y: 4,
  yMin: [2, 1],
  yMax: [5, 6]
}

ESM and Tree Shaking

The ESM build of the library supports tree shaking thus having no side effects. As a consequence the chart.js library won't be automatically manipulated nor new controllers automatically registered. One has to manually import and register them.

Variant A:

import Chart from 'chart.js';
import { BarWithErrorBarsController, RectangleWithErrorBar } from 'chartjs-chart-error-bars';

// register controller in chart.js and ensure the defaults are set
Chart.register(BarWithErrorBarsController, RectangleWithErrorBar);

const chart = new Chart(document.getElementById('canvas').getContext('2d'), {
  type: BarWithErrorBarsController.id,
  data: {
    labels: ['A', 'B'],
    datasets: [
      {
        data: [
          {
            y: 4,
            yMin: 1,
            yMax: 6,
          },
          {
            y: 2,
            yMin: 1,
            yMax: 4,
          },
        ],
      },
    ],
  },
});

Variant B:

import { BarWithErrorBarsChart } from 'chartjs-chart-error-bars';

const chart = new BarWithErrorBarsChart(document.getElementById('canvas').getContext('2d'), {
  data: {
    //...
  },
});

Development Environment

npm i -g yarn
yarn set version 2
yarn
yarn pnpify --sdk vscode

Building

yarn install
yarn build