This guide will walk you through the process of creating a line chart using Plotly.js, a powerful JavaScript library for creating interactive visualizations.

Introduction

Line charts are a great way to visualize data that changes over time. They are particularly useful for showing trends and patterns in your data. Plotly.js makes it easy to create line charts that are both visually appealing and interactive.

Getting Started

Before you can create a line chart, you need to have Plotly.js included in your project. You can include Plotly.js by adding the following script tag to your HTML file:

<script src="https://cdn.plot.ly/plotly-latest.min.js"></script>

Creating a Simple Line Chart

To create a simple line chart, you need two main things: data and a Plotly chart configuration. Here's an example of a simple line chart:

var trace1 = {
  x: [1, 2, 3, 4, 5],
  y: [10, 11, 12, 13, 14],
  type: 'scatter'
};

var data = [trace1];

var layout = {
  title: 'Simple Line Chart',
  xaxis: {
    title: 'X Axis',
    type: 'linear'
  },
  yaxis: {
    title: 'Y Axis',
    type: 'linear'
  }
};

Plotly.newPlot('plot', data, layout);

In this example, we have a single trace with x and y values. We also have a layout that sets the title and axis titles.

Interactivity

Plotly.js allows you to add interactivity to your charts. For example, you can add hover information, zoom in and out, and pan across the chart. Here's an example of how to add hover information:

var trace1 = {
  x: [1, 2, 3, 4, 5],
  y: [10, 11, 12, 13, 14],
  type: 'scatter',
  hoverinfo: 'text'
};

var data = [trace1];

var layout = {
  title: 'Interactive Line Chart',
  xaxis: {
    title: 'X Axis',
    type: 'linear'
  },
  yaxis: {
    title: 'Y Axis',
    type: 'linear'
  }
};

Plotly.newPlot('plot', data, layout);

In this example, we've added the hoverinfo property to the trace, which allows users to see additional information when they hover over the points on the chart.

Further Reading

For more information on Plotly.js and line charts, check out the following resources:

Line Chart Example