# ArrowETC [![PyPI](https://img.shields.io/pypi/v/ArrowETC.svg)](https://pypi.org/project/ArrowETC/) [![CI](https://github.com/carret1268/ArrowETC/actions/workflows/ci.yml/badge.svg)](https://github.com/carret1268/ArrowETC/actions/workflows/ci.yml) [![codecov](https://codecov.io/gh/carret1268/ArrowETC/branch/main/graph/badge.svg)](https://codecov.io/gh/carret1268/ArrowETC) [![GitHub](https://img.shields.io/badge/source-GitHub-black?logo=github)](https://github.com/carret1268/ArrowETC) ## Deprecation Notice Note: This package has been deprecated and is no longer maintained as a standalone module. The functionality of ArrowETC has been fully integrated into the [LogicTreeETC](https://github.com/carret1268/LogicTreeETC) package, which includes not only the ArrowETC arrow-drawing engine, but also logic box layout tools and image feature detection via OpenCV. To continue receiving updates and support, please install the LogicTreeETC package: ```bash pip install logictreeetc ``` And import ArrowETC as follows: ```python from logictree import ArrowETC ``` ArrowETC is a Python library for building flexible, multi-segmented arrows with explicit vertex control -- perfect for precise, publication-quality diagrams. It was designed as a drop-in replacement for matplotlib’s `FancyArrow` and `FancyArrowPatch`, providing far greater control over arrow geometry, corners, and paths. --- ## Motivation While `FancyArrow` and `FancyArrowPatch` in matplotlib offer basic arrow-drawing capabilities, they suffer from limited control: they don’t expose explicit vertex data, they lack support for multi-segment paths, and they provide no access to corner calculations for sharp mitered joints or smooth curves. ArrowETC was created to overcome these limitations by giving full access to the arrow’s properties, allowing: - Multi-segmented arrows with arbitrary bends. - Accurate miter or curved joints. - Optional smooth Bezier curves through control points. - Easy addition of custom arrowheads with precise placement. - Metadata about segment lengths and angles for advanced use. This was essential for building [LogicTreeETC](https://github.com/yourusername/LogicTreeETC), a Python framework for generating logic and decision trees with annotated boxes connected by precise arrows representing information flow. --- ## Features - **Straight or curved arrows**: Draw arrows as straight lines or smooth Bezier curves through path points. - **Multi-bend support**: Create arrows with multiple corners and arbitrary joint angles. - **Precise arrowheads**: Add flared arrowheads with geometry matched to the arrow shaft. - **Explicit geometry access**: Retrieve each polygon vertex for alignment, collision detection, or annotation. - **Matplotlib-ready**: Output vertices directly usable in your matplotlib plots. --- ## Installation ArrowETC requires Python 3.10+ and the packages `numpy`, `matplotlib`, and `scipy`. Install via pip: ```bash pip install arrowetc ``` --- ## Dependencies ArrowETC requires the following Python packages: - `numpy` - `matplotlib` - `scipy` --- ## Examples Below are practical examples showcasing what ArrowETC can do. These scripts generate images demonstrating straight, multi-segmented, and curved arrows with various configurations: ### Matplotlib integration See for a complete example demonstrating how to use ArrowETC as a drop-in replacement for matplotlib arrows. The example shows how to add ArrowETC arrows pointing from annotation boxes to points on a scatter plot, or other annotation boxes, or even specific vertices on another arrow; including straight, segmented, and curved Bezier arrows -- perfect for creating polished, publication-quality figures with precise control over arrow geometry.
matplotlib integration
### Basic arrow with head Draws a straight vertical arrow with an arrowhead at the tip. This demonstrates the simplest use of ArrowETC as a direct replacement for matplotlib’s FancyArrow. ```python path = [(0, 0), (0, 4)] arrow = ArrowETC( path, arrow_width=0.5, arrow_head=True, ec="white", fc="cyan" ) arrow.save_arrow(base_path / "basic_arrow_with_head.png") ```
Basic arrow with head
### Multi-segment arrow with head Draws an arrow that bends twice -- showcasing ArrowETC’s support for arbitrarily segmented arrows with mitered joints. ```python path = [(0, 0), (0, 4), (5, 4), (5, 0)] arrow = ArrowETC( path, arrow_width=0.5, arrow_head=True, ec="white", fc="magenta", lw=2 ) arrow.save_arrow(base_path / "multi_segment_arrow_with_head.png") ```
Multi segment arrow with head
### Obtuse angle arrow Illustrates how ArrowETC handles obtuse bends smoothly with obtuse corners. ```python path = [(0, 0), (4, 0), (8, 2)] arrow = ArrowETC( path, arrow_width=0.5, arrow_head=True, ec="white", fc="orange" ) arrow.save_arrow(base_path / "obtuse_arrow_with_head.png") ```
Obtuse arrow with head
### Acute angle arrow Shows an arrow with an acute angle, where the shaft sharply turns -- highlighting ArrowETC’s ability to produce clean miters even for tight angles. ```python path = [(0, 0), (4, 0), (1, 4)] arrow = ArrowETC( path, arrow_width=0.5, arrow_head=True, ec="white", fc="cyan" ) arrow.save_arrow(base_path / "acute_arrow_with_head.png") ```
acute arrow with head
### More complex multi-segmented arrow Shows how the ArrowETC object can handle more complicated paths. ```python path = [(0, 0), (1, 2), (2, -1), (4, -2), (5, 0), (7, 0)] arrow = ArrowETC( path, arrow_head=True, arrow_width=0.2, ec="white", fc="cyan" ) arrow.save_arrow(base_path / "many_segments_with_head.png") ```
More complex multi-segmented arrow
### Multi-segmented arrow without arrowhead Creates a segmented rectangular “pipe” without an arrowhead, useful for process diagrams or connectors where a directional tip is unnecessary. ```python path = [(0, 0), (0, -10), (10, -10), (10, 0)] arrow = ArrowETC( path, arrow_width=1, arrow_head=False, ec="white", fc="cyan" ) arrow.save_arrow(base_path / "multi_segment_no_head.png") ```
Multi segment with no arrow head
### Basic Bezier arrow with head Uses a smooth Bezier curve instead of straight segments. ```python path = [(0, 0), (4, 0), (8, 2)] arrow = ArrowETC( path, arrow_width=0.5, arrow_head=True, bezier=True, ec="white", fc="orange" ) arrow.save_arrow(base_path / "basic_bezier_with_head.png") ```
Basic bezier with head
### Complex Bezier arrows - **Low bezier_n**: `bezier_n=400` -- demonstrates how too few sample points can distort the arrowhead or tip on sharp, complex curves. ```python path = [(0, 0), (4, -5), (8, 2), (16, -8)] arrow = ArrowETC( path, arrow_width=1, arrow_head=True, bezier=True, ec="white", fc="cyan" ) arrow.save_arrow(base_path / "crazier_bezier_with_head-low_n.png") ```
Crazier bezier with head - low n
- **High bezier_n**: `bezier_n=800` -- shows a smooth, high-resolution arrow even along aggressive curves, fixing tip skew. ```python path = [(0, 0), (4, -5), (8, 2), (14, -8)] arrow = ArrowETC( path, arrow_width=1, arrow_head=True, bezier=True, bezier_n=800, ec="white", fc="cyan", ) arrow.save_arrow(base_path / "crazier_bezier_with_head-high_n.png") ```
Crazier bezier with head - high n
These examples illustrate how ArrowETC can handle everything from straight connectors to advanced, smooth curved paths -- making it an ideal replacement for matplotlib’s limited arrow types, and a powerful tool for your custom diagrams. For reference, all example scripts are included in the `examples/` directory. The generated images are saved in the `resources/` directory. ## Development This project uses the following tools for code quality and security: - **Ruff**: for fast linting and auto-formatting checks. - **mypy**: for static type checking. - **Bandit**: for security scanning. - **GitHub Actions CI**: runs tests, type checks, linting, and security checks on every push. - **Dependabot**: automatically checks for dependency updates. See the [.github/workflows/](https://github.com/carret1268/ArrowETC/tree/main/.github/workflows) directory for CI configurations. ## License This project is licensed under a CC0 License. See LICENSE file for details. ## GitHub Link [GitHub](https://github.com/yourusername/ArrowETC) --- ```{toctree} :maxdepth: 2 :caption: Contents: api ```