Recipe: Habit Heatmap

Visualize daily habit completion as a calendar heatmap.

The Result

A heatmap showing habit completion intensity across days.

Basic Heatmap

```dg
type: heatmap
data:
  source: '[
    {"week": "W1", "day": "Mon", "completed": 3},
    {"week": "W1", "day": "Tue", "completed": 5},
    {"week": "W1", "day": "Wed", "completed": 4},
    {"week": "W1", "day": "Thu", "completed": 2},
    {"week": "W1", "day": "Fri", "completed": 5},
    {"week": "W1", "day": "Sat", "completed": 3},
    {"week": "W1", "day": "Sun", "completed": 1},
    {"week": "W2", "day": "Mon", "completed": 4},
    {"week": "W2", "day": "Tue", "completed": 5},
    {"week": "W2", "day": "Wed", "completed": 5},
    {"week": "W2", "day": "Thu", "completed": 3},
    {"week": "W2", "day": "Fri", "completed": 4},
    {"week": "W2", "day": "Sat", "completed": 2},
    {"week": "W2", "day": "Sun", "completed": 2}
  ]'
x: day
y: week
color: completed
title: Weekly Habit Tracker
```

From Daily Notes

If you track habits in daily notes with frontmatter:

---
date: 2024-01-15
habits:
  exercise: true
  reading: true
  meditation: false
  journaling: true
---

Create a dataview-style query:

```dg
type: heatmap
data:
  query: from:Daily where:date:2024-01
transformations:
  - type: derive
    configuration:
      day: "new Date(date).getDay()"
      week: "Math.ceil(new Date(date).getDate() / 7)"
      score: "habits.exercise + habits.reading + habits.meditation + habits.journaling"
x: day
y: week
color: score
title: January Habits
```

Customizations

Green color scale (GitHub style):

colorScheme: "greens"

Show values in cells:

showValues: true

Custom color range:

scales:
  color:
    domain: [0, 5]
    range: ["#eee", "#22c55e"]

Reverse order (newest on top):

scales:
  y:
    reverse: true

Pro Tip

Combine with a summary bar chart:

```dg
type: bar
data:
  file: data/habits.csv
transformations:
  - type: aggregate
    configuration:
      groupBy: ["habit"]
      sum: ["completed"]
x: habit
y: completed_sum
title: Total Completions by Habit
```