Sankey diagrams, named after Sankey and introduced in 1898, are a specific type of flow diagram used to visualize energy or material flows. They are particularly useful in illustrating processes in which a quantity goes through a series of continuous changes. The Sankey diagram’s innovative approach to data visualization makes it particularly effective for showing the distribution of data across different categories or stages, enabling a clear comparison and highlighting significant changes in magnitude of data flow or size.
Creating a Sankey Chart
The creation of a Sankey chart involves several steps that ensure the end result is not only visually appealing but also conveys the intended message effectively. The process is relatively straightforward but requires attention to detail to ensure accuracy and clarity.
1. Data Collection
Before even starting to create the Sankey diagram, it’s crucial to collect the right kind of data. This usually involves gathering the amount or quantity flowing between different stages or categories, ensuring that the data represents a continuous flow.
2. Data Transformation
Once you have your data, it needs to be transformed into a form that can be used in a Sankey diagram. This often involves categorizing the data into distinct categories that represent the different stages or categories the data moves through.
3. Choosing a Tool
There are many tools you can use to create a Sankey diagram. Some popular options include R with ggplot2 and ggsankey, Python with Plotly or matplotlib, and even Excel with its Power Query and Charts features. Each tool has its own set of advantages depending on your proficiency and the aesthetics you wish to achieve.
4. Designing the Layout
With your data in hand and a tool selected, it’s time to start designing the layout. The goal is to ensure each flow visually represents the underlying data accurately. This includes setting the widths of the links to correspond with their magnitudes, ensuring the distribution across categories is balanced and clear, and choosing colors that help highlight the data flow.
5. Adding Annotations
Labeling the nodes and links is crucial for clarity. Make sure to use annotations that accurately describe the stages or categories and numbers that represent the flow magnitudes. Avoid clutter by being precise and adding only what is necessary to effectively tell the story.
6. Review and Refinement
Before presenting or publishing the diagram, take a step back to review it critically. Evaluate whether it effectively communicates the intended message, whether the colors and layout complement each other, and whether the flow appears natural. Make necessary adjustments to refine the visual.
Applications of Sankey Charts
Sankey diagrams have proven their utility in various fields and applications beyond their initial use in mechanical engineering. Here are some of the popular applications:
- Energy Flow Analysis: One of the most common applications is to illustrate energy flows between processes, highlighting energy losses and efficiencies.
- Data Migration: Used in databases and software development to visualize the flow of data between different systems and transformations.
- Environmental Studies: Showing the environmental flows from one stage to another, such as water flows in a river system or emissions from a factory.
- Supply Chain Analysis: Visualizing the flow of materials and products through a supply chain, including manufacturing, distribution, and consumer use.
- Economic Research: Identifying how money moves through different sectors of an economy or illustrating the flow of financial transactions.
Sankey diagrams are not just tools for data visualization; they are storytelling devices that can reveal the underlying processes and relationships in a way that is accessible and engaging. Whether looking at the energy efficiency of a building, the financial flows in a country, or the data handling of a large organization, the art of storytelling with Sankey charts is a powerful way to make complex processes understandable and transparent.
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.
