matplotlib

A Python library for creating static, animated, and interactive charts with detailed control over their appearance. It can export figures as PNG, PDF, or SVG files.

In plain words
What is it for?
Use it for scientific and statistical plots, multi-panel figures, heatmaps, contours, 3D charts, animations, and publication-ready exports.
Why use it?
It is useful when a quick chart is not enough and you need to control labels, layout, styling, or unusual visual elements precisely.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/tobiasblask/open-paper-machine/matplotlib
Any agent
npx skills add TobiasBlask/open-paper-machine --skill matplotlib
Clone the repo
git clone --depth 1 https://github.com/TobiasBlask/open-paper-machine

Made for: Claude Code, Codex.

Per session 77 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,953 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00077 $0.02953
Opus 5 $0.00039 $0.01477
Sonnet 5 $0.00015 $0.00591
Haiku 4.5 $0.00008 $0.00295

Measured 2d ago against content hash 20aaffc4ca73, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

matplotlib scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/plot_template.py, scripts/style_configurator.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to matplotlib — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

scientific-skills/matplotlib/SKILL.md · 360 lines

How it starts

The opening of the file, as written. The whole thing — 360 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Matplotlib

Overview

Matplotlib is Python's foundational visualization library for creating static, animated, and interactive plots. This skill provides guidance on using matplotlib effectively, covering both the pyplot interface (MATLAB-style) and the object-oriented API (Figure/Axes), along with best practices for creating publication-quality visualizations.

When to Use This Skill

This skill should be used when:

  • Creating any type of plot or chart (line, scatter, bar, histogram, heatmap, contour, etc.)
  • Generating scientific or statistical visualizations
  • Customizing plot appearance (colors, styles, labels, legends)
  • Creating multi-panel figures with subplots
  • Exporting visualizations to various formats (PNG, PDF, SVG, etc.)
  • Building interactive plots or animations
  • Working with 3D visualizations
  • Integrating plots into Jupyter notebooks or GUI applications

Core Concepts

The Matplotlib Hierarchy

Matplotlib uses a hierarchical structure of objects:

  1. Figure - The top-level container for all plot elements
  2. Axes - The actual plotting area where data is displayed (one Figure can contain multiple Axes)
  3. Artist - Everything visible on the figure (lines, text, ticks, etc.)
  4. Axis - The number line objects (x-axis, y-axis) that handle ticks and labels

Two Interfaces

1. pyplot Interface (Implicit, MATLAB-style)

import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 4])
plt.ylabel('some numbers')
plt.show()
  • Convenient for quick, simple plots
  • Maintains state automatically
  • Good for interactive work and simple scripts

2. Object-Oriented Interface (Explicit)

import matplotlib.pyplot as plt

fig, ax = plt.subplots()
ax.plot([1, 2, 3, 4])
ax.set_ylabel('some numbers')
plt.show()
  • Recommended for most use cases
  • More explicit control over figure and axes
  • Better for complex figures with multiple subplots
  • Easier to maintain and debug

Common Workflows

1. Basic Plot Creation

Read the full file on GitHub · 360 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 360 lines · 77 tokens per session scan A 20aaffc4ca73

Subscribe to this mod's changes

matplotlib is a skill published in the GitHub repository TobiasBlask/open-paper-machine (18 stars, last pushed 4mo ago), licensed MIT. It adds 77 tokens to every session and 2,953 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to matplotlib, differing in 0 lines, and is treated as a copy.