Heatmap

Use a heatmap to see how a numeric value varies across two categories, such as weekday and hour.

Source

```chart
type: heatmap
title: Deploys by weekday and hour (UTC)
data:
  inline:
    - { weekday: Mon, hour: "09", deploys: 2 }
    - { weekday: Mon, hour: "12", deploys: 4 }
    - { weekday: Mon, hour: "15", deploys: 6 }
    - { weekday: Tue, hour: "09", deploys: 4 }
    - { weekday: Tue, hour: "12", deploys: 7 }
    - { weekday: Tue, hour: "15", deploys: 9 }
    - { weekday: Wed, hour: "09", deploys: 3 }
    - { weekday: Wed, hour: "12", deploys: 5 }
    - { weekday: Wed, hour: "15", deploys: 7 }
encoding: { x: hour, y: weekday, color: deploys }
```

Fields that matter

• type: heatmap with encoding.x and encoding.y as the two categorical axes
• encoding.color is the cell value
• axes.color sets format and unit for cell values
• One numeric value per cell; repeated coordinates reject the chart
• Missing values show as a neutral n/a cell
• The default palette is monotone, and heatmaps have no color bar

Interactions

• Hover or focus a cell to read its coordinates and value.
• Open the Table view, Download PNG or CSV, or Expand the chart.