# Chart Picker

> Chart Picker

- Skill: `utxo-ag/chart-picker` (Agent Skill)
- Install (CLI): `npx skillmds@latest add utxo-ag/chart-picker`
- Raw SKILL.md: https://api.skillmd.com/api/skills/utxo-ag/chart-picker/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: utxo-AG (https://skillmd.com/u/utxo-ag)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/utxo-ag/chart-picker

---

# Chart Picker

Recommend the best visualization or chart type for a given dataset.

## Workflow

1. **Classify variables** — For each column/field in the dataset, determine whether it is numeric or categorical. Dates and timestamps count as ordered numeric.
2. **Count variables** by type and note characteristics:
   - How many numeric variables? How many categorical?
   - Is there an ordering (e.g., time series)?
   - How many data points? (few ≈ < 30, many ≈ 30+)
   - Are categorical groups nested or subgrouped?
   - Is the data an adjacency/relationship structure (e.g., flows, networks)?
3. **Walk the decision tree** below to find matching chart types.
4. **Recommend 1-3 charts** with a one-sentence rationale for each. Prefer the first option listed when multiple charts fit equally well.
5. If the dataset characteristics are ambiguous, ask the user a clarifying question before recommending.

---

## Decision Tree

### Numeric

#### One Numeric Variable

- **Few data points** → Scatter Plot, Histogram, Box Plot
- **Many data points** → Density Plot, Scatter with Marginal Points, 2D Density Plot

#### Two Numeric Variables

- **Not ordered** → Scatter Plot, Histogram, Box Plot
- **Ordered** (e.g., time series) → Area Plot, Line Plot, Connected Scatter Plot

#### Three Numeric Variables

- **Not ordered** → Bubble Plot, 3D Scatter or Surface, Violin Plot, Box Plot
- **Ordered** → Bubble Plot, 3D Scatter or Surface, Violin Plot, Box Plot

#### Several Numeric Variables

- **Not ordered** → Correlogram
- **Ordered** → Line Plot, Area (Small Multiple), Streamgraph, Stacked Area Plot

#### Summary Views (many numeric variables)

Ridgeline, Violin Plot, Box Plot, Dendrogram, Heatmap, PCA

---

### Categoric

#### One Categorical Variable

Bar Plot, Lollipop, Waffle, Word Cloud, Doughnut, Pie, Treemap, Circular Packing

#### Two or More Categorical Variables

- **Subgroup** → Grouped Bar Plot, Stacked Bar Plot, Lollipop, Heatmap, Parallel Plot, Spider Plot, Grouped Scatter
- **Nested** → Treemap, Circular Packing, Sunburst, Dendrogram, Bar Plot
- **Two independent lists** → Venn Diagram

#### Adjacency (relationships / flows)

Network, Chord, Arc, Sankey, Heatmap

---

### Num & Cat (mixed numeric + categorical)

#### One Numeric, One Categorical

- **One observation per group** → Barplot, Lollipop, Pie, Doughnut, Wordcloud, Waffle, Circular Packing, Treemap
- **Several observations per group** → Violin, Boxplot

#### Several Categorical, One Numeric

- **Nested** → Barplot, Dendrogram, Sunburst, Circular Packing, Treemap
- **Subgroup**
  - One observation per group → Barplot, Lollipop, Grouped Scatter, Heatmap, Grouped Bar Plot, Stacked Bar Plot, Parallel Plot, Spider Plot, Sankey Diagram
  - Several observations per group → Violin, Boxplot

#### One Categorical, Several Numeric

- **No order** → Grouped Scatter, 2D Density, Violin, Boxplot, PCA, Correlogram
- **A numeric is ordered**
  - Multiple observations per group → Area, Stacked Area, Streamgraph, Line Plot, Connected Scatter
  - One value per group → Grouped Scatter, Heatmap, Lollipop, Grouped Bar Plot, Stacked Bar Plot, Parallel Plot, Spider Plot, Sankey Diagram

#### Adjacency (relationships / flows with weights)

Network, Chord, Arc, Sankey, Heatmap

---

## Tips

- **Time series** data (date/dateHour dimension + one metric) → Line Plot or Area Plot is almost always the best choice.
- **Top-N rankings** (e.g., top pages by views) → Horizontal Bar Plot or Lollipop.
- **Part-of-whole** (e.g., traffic by channel) → Stacked Bar Plot, Treemap, or Pie/Doughnut (only if ≤ 6 slices).
- **Comparison across groups** (e.g., metrics by device category) → Grouped Bar Plot or Radar/Spider.
- **Distribution** of a single metric → Histogram, Density Plot, or Box Plot.
- **Correlation** between two metrics → Scatter Plot.
- When in doubt between similar charts, prefer the simpler one.