Heat Map

Anatomy
Text on a chart refers to any written information or labels included in a chart to provide context, describe data, or improve the readability and understanding of the visualization.
 label in a heatmap refers to the text that identifies rows, columns, or specific data points. Labels provide context and help users understand what each axis or cell represents.
 The data item refers to the actual value or metric represented by each cell in the heatmap. The intensity of the color in each cell corresponds to the magnitude of the data item
 The level in a heatmap refers to the range or category of values represented by specific color intensities. Levels are often defined by thresholds or gradients to show data distribution.
 A small box that pops up when you hover over a data point, showing more details about it.
 A bar that lets you move around the chart when there’s too much data to fit on the screen.
Guidelines for Heat Map
- Number of Digits: Use a maximum of 3 digits for ease of reading.
- Decimal Points: limit to 2 decimal places for clarity. Example, use '12.34' instead of '12.3456'.
- Diverging Colors: According to the diverging color palette, Heat Map diagrams can use these colors to represent conditional data.z
- Sequential: In addition to a diverging color palette, you can also use a sequential color palette from green to red.
- Add a legend to explain the color gradation and corresponding value.
Example of Source Data

When to Use a Heat Map?
- Displays data density and variation.​
- Identifies patterns and correlations.​
- Suitable for large data sets where specific values ​​are less important than the overall value.​
- Use color coding to visualize value status: red for over budget , green for on budget, yellow for threshold border.​