Tableau Tutorial - How to Create a Dual Axis (layered) Map in Tableau

Introduction

This tutorial will guide you on how to create a Dual-Axis Map in Tableau, which allows you to overlay two sets of geographic data. This visualization is useful for analyzing relationships between two data sets, such as customer locations and store locations, and can help identify areas for potential new store openings.

Step 1: Prepare Your Data

• Ensure your dataset contains two sets of geographic points. In this example, you will use:
  • Customer ZIP codes
  • Store ZIP codes
• Import your data into Tableau.

Step 2: Create a New Sheet

• Open a new worksheet in Tableau.
• Drag the "Store ZIP" field to the view to start plotting the store locations.

Step 3: Add Latitude for the Stores

• Find the generated latitude field for the store locations.
• Hold down the Control key (Ctrl) and drag the latitude field to create a second latitude layer.

Step 4: Create Dual-Axis

• Right-click on the second latitude field.
• Select "Dual Axis" to combine the two layers into one map.

Step 5: Configure the Map Layers

• The bottom latitude field will represent stores while the top layer will show customer locations.
• Drag the "Customer ZIP" field to the top layer to overlay customer points.
• Adjust the colors for better visibility:
  • Set customer points to green.
  • Set store points to blue.
• Modify the size and opacity:
  • Make the store points larger with 80% opacity and a black outline.
  • Adjust customer points to a smaller size with 50% opacity.

Step 6: Analyze the Map

• Examine the map to identify areas with a high density of customers but low store presence.
• For example, look for regions in New Mexico, Colorado, South Dakota, Kentucky, and Tennessee where there are few stores serving many customers.

Step 7: Create a Longitude Dual-Axis Map (Optional)

• For a different perspective, create another new sheet.
• Instead of latitude, drag the "Store Longitude" field to the view.
• Control-click to create a second longitude layer.
• Repeat the dual-axis creation process and adjust the visualization as done in Step 5.

Step 8: Conduct Further Analysis

• Use the dual-axis map to analyze specific regions, such as Texas, to determine potential new store locations based on customer distributions.

Conclusion

You have successfully created a Dual-Axis Map in Tableau to visualize and analyze customer and store locations. This technique provides valuable insights for business decisions, such as where to open new stores based on customer density. For further learning, consider exploring additional Tableau features or creating dashboards to enhance your data visualization capabilities.