Flowing Through Data: The Art and Science of Sankey Charts
Exploring the innovative way of visualizing how data flows between different processes, Sankey charts offer a unique blend of artistry and science, making complex data flows easier to understand and interpret. This visual tool is not only a marvel of data visualization but also a powerful method for exploring and presenting data, making it indispensable in various fields including economics, sustainability, and engineering. Below, we delve into the creation of Sankey charts, their applications, and the insights they offer to help better understand the intricacies of data flow.
The Science of Sankey Charts
Sankey charts, named after Edward Davy’s secretary, Mark Barr, after whom the letter “B” in “Bar” was added to the charts developed by Irish engineer, John Ambrose Fleming, are named after, have several characteristics that make them ideal for data visualization. Unlike traditional bar charts or pie charts, Sankey diagrams represent data flow with streams of varying width, where the width of each stream corresponds to the quantity transferred from one data point to another. This direct correlation between visual representation and the relative size of data points makes Sankey diagrams incredibly intuitive and effective.
Creating a Sankey Chart
Creating a Sankey chart efficiently involves several steps:
Step 1: Data Preparation
Sankey diagrams work best with data that shows a series of interlinked processes where quantities move from one process to another. Your data must be in the right format – typically, you’ll need to organize your data into three columns: From, To, and Value, where the Value indicates the quantity flowing between the From and To processes.
Step 2: Data Validation
Ensure each unique point in your data (From and To columns) is represented accurately and that all values are correctly calculated to show a net gain or loss. For instance, if A → B and B → A represents a one-to-one flow, calculate the net value to avoid redundancy and ensure clarity.
Step 3: Data Visualization
Various tools and software, including R (with ggalluvial, d3.js), Python (with Plotly, Bokeh, or Dash), and Excel (with Power BI), offer built-in or user-defined templates for creating Sankey diagrams. These tools simplify the process and enable users to customize the look and feel of their chart.
Step 4: Insights Generation
Once your Sankey diagram is created, it’s essential to analyze it to derive meaningful insights. Look for major flows, identify if there are any processes that “vampire” other processes (large losses or gains, especially with no net flow), and explore correlations between different processes.
Applications of Sankey Charts
Sankey diagrams are versatile and have wide applications, with their unique ability to visualize the flow of data making them invaluable. Major use cases include:
Sustainability and Resource Management
Environmentalists use Sankey diagrams to explore and educate the public about the flow of resources, energy, and emissions in a system, making complex data understandable and engaging.
Supply Chain Analysis
Business and economics professionals use them to analyze supply chains, understand the flow of goods, and identify inefficiencies or bottlenecks in the system.
Financial Flow Analysis
Sankey diagrams help analysts and investors navigate and understand complex financial flows, relationships, and investments, providing a comprehensive overview of the financial landscape.
Healthcare Flows
In the healthcare sector, Sankey diagrams are used to analyze the flow of patients, resources, and costs within a hospital or clinic, highlighting areas of cost and time inefficiency.
Social Network Analysis
Sankey diagrams are also used to visualize information flow and social networks, aiding in the understanding of how messages, opinions, and information propagate through a network of individuals.
The Art of Creating Effective Sankey Charts
Creating effective Sankey diagrams involves a careful balance of aesthetics and functionality. Choose colors that are informative yet minimal, ensuring the primary information remains clear and uncluttered. Consider the hierarchy of flows, ensuring the most significant flows are visually the most prominent. Finally, include a legend or explanation of the chart, ideally integrated within the chart itself to avoid user confusion.
Conclusion
Sankey charts are a powerful tool for exploring complex data flows, with applications across various fields. By understanding how to create and interpret these diagrams, individuals can unlock valuable insights from their data, making visual analysis not just possible but accessible. As data continues to grow exponentially, the Sankey chart will no doubt continue to evolve, offering new ways to understand and navigate the vast networks of information surrounding us.
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.
