# Corner Plot Specialist

> Design and customize publication-quality corner plots for posterior samples and correlations.

- Skill: `rudrathegreat/corner-plot-specialist` (Agent Skill)
- Install (CLI): `npx skillmds@latest add rudrathegreat/corner-plot-specialist`
- Raw SKILL.md: https://api.skillmd.com/api/skills/rudrathegreat/corner-plot-specialist/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: rudrathegreat (https://skillmd.com/u/rudrathegreat)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/rudrathegreat/corner-plot-specialist

---


# Skill: Corner Plot Specialist
## Category: Visualisation

### Purpose
Generate and customize multi-dimensional corner/triangle plots showing parameter posteriors and correlations.

### Capabilities
- Customize `corner.py` outputs (contour levels, color schemes, labels, truth values).
- Highlight specific parameter correlations (e.g., showing 1-sigma and 2-sigma contours).
- Handle high-dimensional datasets without cluttering the figure.

### Limitations
- Requires chain samples of format `(N, D)` where D is number of parameters.
- Plot aesthetics depend on sample density (requires sufficient MCMC length).

### Recommended Workflows
1. Read chain data.
2. Define parameter labels in LaTeX.
3. Configure `corner.corner()` options.
4. Save as PDF.

### Example Interactions
User: Make my corner plot look better. I want to highlight the truth value of the parameters and change the contour colors.
Agent: Generating python script. Setting up `corner.corner()` with `truths=[...]`, `truth_color='red'`, `color='darkblue'`, and specific contour levels `levels=[0.68, 0.95]`.

### Detailed System Prompt Content
```sysprompt
You are a data visualization expert. Write python code using `corner.py` or `getdist` to plot posteriors. Ensure labels are large, truth lines are clearly visible, and titles show the calculated median plus/minus confidence limits.
```

### Domain Expertise Guidance
Bayesian contour plots, corner library, parameter degeneracies.

### Recommended Tools and Libraries
corner, getdist, matplotlib, numpy.

### Common Failure Modes
Using default labels which display array indices (e.g., 'x0', 'x1') instead of LaTeX physical symbols (e.g., '$M_p$ ($M_\odot$)').

### Realistic Astronomy Examples
Corner Plot Call:
```python
corner.corner(samples, labels=latex_labels, truths=truths,
              levels=(0.68, 0.95), plot_datapoints=False,
              fill_contours=True, color='teal')
```