--- name: plotext-financial-chart description: ASCII financial line charts for markdown using plotext dot marker. TRIGGERS - financial chart, line chart, plotext, price chart, trading chart, ASCII chart. allowed-tools: Read, Bash, Write, Edit --- # Plotext Financial Chart Skill Create ASCII financial line charts for GitHub Flavored Markdown using plotext with dot marker (`•`). Pure text output — renders correctly on GitHub, terminals, and all monospace environments. **Analogy**: `graph-easy` is for flowcharts. `plotext` with dot marker is for financial line charts. > **Self-Evolving Skill**: This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues. ## When to Use This Skill - Adding price path / line chart diagrams to markdown documentation - Visualizing trading concepts (barriers, thresholds, entry/exit levels) - Any GFM markdown file needing financial data visualization - User mentions "financial chart", "line chart", "price chart", "plotext", or "trading chart" **NOT for**: Flowcharts or architecture diagrams — use `graph-easy` for those. ## Preflight Check ### All-in-One Preflight Script ```bash /usr/bin/env bash << 'PREFLIGHT_EOF' python3 --version &>/dev/null || { echo "ERROR: Python 3 not found"; exit 1; } if command -v uv &>/dev/null; then PM="uv pip" elif command -v pip3 &>/dev/null; then PM="pip3" else echo "ERROR: Neither uv nor pip3 found"; exit 1; fi python3 -c "import plotext" 2>/dev/null || { echo "Installing plotext via $PM..."; $PM install plotext; } python3 -c " import plotext as plt, re plt.clear_figure() plt.plot([1,2,3], [1,2,3], marker='dot') plt.plotsize(20, 5) plt.theme('clear') output = re.sub(r'\x1b\[[0-9;]*m', '', plt.build()) assert '•' in output " && echo "✓ plotext ready (dot marker verified)" PREFLIGHT_EOF ``` ## Quick Start ```python import re import plotext as plt x = list(range(20)) y = [97, 98, 100, 101, 100, 98, 100, 101, 102, 101, 100, 98, 100, 101, 102, 103, 102, 101, 100, 100] plt.clear_figure() plt.plot(x, y, marker="dot", label="Price path") plt.hline(103) # Upper barrier plt.hline(97) # Lower barrier plt.hline(100) # Entry price plt.title("Triple Barrier Method") plt.xlabel("Time (bars)") plt.ylabel("Price") plt.plotsize(65, 22) plt.theme("clear") print(re.sub(r'\x1b\[[0-9;]*m', '', plt.build())) ``` ## Mandatory Settings Every chart MUST use these settings: | Setting | Code | Why | | --------------- | --------------------------- | ---------------------------- | | Reset state | `plt.clear_figure()` | Prevent stale data | | Dot marker | `marker="dot"` | GitHub-safe alignment | | No color | `plt.theme("clear")` | Clean text output | | Strip ANSI | `re.sub(r'\x1b\[…', '', …)` | Remove residual escape codes | | Build as string | `plt.build()` | Not `plt.show()` | ## Marker Reference | Marker | GitHub Safe | Use When | | ----------- | ----------- | ------------------------------ | | `"dot"` | Yes | **Default — always use** | | `"hd"` | Yes | Terminal-only, need smoothness | | `"braille"` | No | Never for markdown | | `"fhd"` | No | Never — Unicode 13.0+ only | ## Rendering Command ```bash /usr/bin/env bash << 'RENDER_EOF' python3 << 'CHART_EOF' import re import plotext as plt x = list(range(20)) y = [97, 98, 100, 101, 100, 98, 100, 101, 102, 101, 100, 98, 100, 101, 102, 103, 102, 101, 100, 100] plt.clear_figure() plt.plot(x, y, marker="dot", label="Price path") plt.hline(103) plt.hline(97) plt.hline(100) plt.title("Triple Barrier Method") plt.xlabel("Time (bars)") plt.ylabel("Price") plt.plotsize(65, 22) plt.theme("clear") print(re.sub(r'\x1b\[[0-9;]*m', '', plt.build())) CHART_EOF RENDER_EOF ``` ## Embedding in Markdown (MANDATORY: Source Adjacent to Chart) Every chart MUST be **immediately followed** by a `
` block with Python source. Explanatory text goes **after** the `
` block, never between chart and source. ``` ✅ CORRECT: Chart →
→ Explanatory text ❌ WRONG: Chart → Explanatory text →
``` See [./references/api-and-patterns.md](./references/api-and-patterns.md) for full embedding template. ## Mandatory Checklist - [ ] `plt.clear_figure()` — Reset state - [ ] `marker="dot"` — Dot marker for GitHub - [ ] `plt.theme("clear")` + `re.sub()` strip — No ANSI codes - [ ] `plt.title("...")` — Every chart needs a title - [ ] `plt.xlabel` / `plt.ylabel` — Axis labels - [ ] `plt.plotsize(65, 22)` — Fits 80-col code blocks - [ ] `
` block **immediately after** chart (before any explanatory text) ## Troubleshooting | Issue | Cause | Solution | | --------------------- | ------------------- | --------------------------------------------- | | ANSI codes in output | Missing theme/strip | Add `plt.theme("clear")` and `re.sub()` strip | | Misaligned on GitHub | Wrong marker type | Use `marker="dot"`, never braille/fhd | | Chart too wide | plotsize too large | Use `plt.plotsize(65, 22)` for 80-col blocks | | No diagonal slopes | Too few data points | Use 15+ data points for visible slopes | | `ModuleNotFoundError` | Not installed | Run preflight check | | Empty output | Missing `build()` | Use `plt.build()` not `plt.show()` | ## Resources - [plotext GitHub](https://github.com/piccolomo/plotext) - [Full API, patterns, and embedding guide](./references/api-and-patterns.md) - [Tool selection rationale](./references/tool-selection.md) ## Post-Execution Reflection After this skill completes, check before closing: 1. **Did the command succeed?** — If not, fix the instruction or error table that caused the failure. 2. **Did parameters or output change?** — If the underlying tool's interface drifted, update Usage examples and Parameters table to match. 3. **Was a workaround needed?** — If you had to improvise (different flags, extra steps), update this SKILL.md so the next invocation doesn't need the same workaround. Only update if the issue is real and reproducible — not speculative.