Sankey charts are a popular visualization tool for representing flows between different categories or nodes. These charts are named after the Scottish engineer and civil engineer, Matthew Henry Phineas Riall (Heinrich Wilhelm) Sankey, who introduced them in the 19th century to demonstrate how energy was being used in steam engine factories. Since then, Sankey diagrams have found applications in various fields, such as economics, ecology, engineering, etc. This article will provide a comprehensive guide on creating compelling Sankey charts for data visualization needs.

What is a Sankey Chart?

A Sankey chart is a directed graph that represents flows between different categories or nodes. The flow represents the quantity of items moving between categories. It uses arrows or pipes to connect categories and indicates the magnitude of the flow by the width and color of the connection. Sankey diagrams are particularly handy for visualizing complex relationships, flow processes, and material or energy conservation, making them a valuable tool for researchers, engineers, economists, and data scientists.

Key Components of a Sankey Chart

Sankey charts have several standard components:

• Source: The category from where the flow originates.
• Target: The category to which the flow is directed.
• Flow: The quantity or amount of the items/energy passing between the source and target.
• Value: The intensity of the flow, represented by the width of the arrow or pipe.

How to Create a Compelling Sankey Chart

Creating a compelling Sankey chart involves several steps:

1. Define Your Data

Before creating a Sankey chart, ensure you have access to a clear, structured dataset. The data should include information about the source, target, and flow of items. You may need to transform your raw data to get it in the correct format for a Sankey chart.

2. Choose a Tool or Library

There are several tools and libraries that can help you create Sankey charts:

• D3.js: A powerful JavaScript library that offers extensive customization of Sankey diagrams.
• Plotly: Provides easy-to-use API for creating interactive Sankey diagrams using other languages like Python, R, and JavaScript.
• Matplotlib and Seaborn (for Python users): They provide built-in functions to create Sankey charts.

3. Design the Data Structure

Use standard data structures for the Sankey chart, such as nodes and links. The nodes should include categories, and links should include source nodes, target nodes, and flows.

4. Prepare Your Data for Visualization

With the appropriate structure in place, format your data for the visualization library. Ensure you include necessary properties like source, target, value, and any additional aesthetic properties such as color or labels.

5. Set Up Your Chart

Choose a layout, typically horizontal or vertical, and customize the appearance of links, nodes, and other visual elements. Adjust colors, labels, and any other desired settings for enhanced clarity and aesthetics.

6. Add Interactivity (if necessary)

For an engaging presentation, add interactive elements like tooltips, zoom, and filters, which can significantly enhance user experience.

7. Test Your Chart

Before finalizing, ensure that the chart is clear and easy to understand. Test all features to ensure they work correctly.

Applications of Sankey Charts

Energy Consumption

Sankey charts have been used to visualize energy flow and efficiency within a system, allowing stakeholders to identify potential areas for improvement. For instance, in oil refineries or industrial plants, these charts can help in highlighting energy loss and identify more efficient processes.

Material Flow Analysis

Often seen in supply chain management, these diagrams help companies optimize their production processes and waste management practices. By analyzing material flow, businesses can reduce costs and environmental impact.

Economics

In economics, Sankey charts show the flow of goods and services between countries or industries. They can offer insights into global trade patterns, aid in identifying economic impacts of policy changes, and more.

Conclusion

Creating a compelling Sankey chart allows you to represent and analyze complex flows of items, energy, or information in a visually engaging and informative manner. By following the steps presented, you can produce effective Sankey diagrams that will enhance the comprehension of your audience and add value to your data analysis. Incorporating tools and libraries that specialize in these diagrams can streamline the creation process and enable you to customize the charts to your specific needs, making the analysis both powerful and visually appealing.

SankeyMaster

SankeyMaster is your go-to tool for creating complex Sankey charts . Easily enter data and create Sankey charts that accurately reveal intricate data relationships.