Grapher

A lightweight, no-frills 2D plotting tool written in pure C for when the internet abandons you but graphs don't.

Overview

Grapher is a minimalist graphing utility born out of necessity during an internet-deprived trip. When fancy graphing libraries aren't available but you still need to visualize data, Grapher has your back. It generates simple bitmap (PBM) visualizations from point data.

Features

• Dependency-free: Just plain C, no external libraries needed
• Portable: Works wherever a C compiler exists
• Small footprint: Tiny codebase that's easy to understand and modify
• Paired with a data generator: Generate test data with configurable mathematical functions

How It Works

Grapher takes a binary data file of x,y coordinates and renders them as a bitmap image. The companion generator tool can create test data following mathematical patterns.

Components

• main.c: The core graphing logic
• defs.h: Core definitions and file handling
• fileio.h: File I/O utilities
• generator.c: Test data generator (follows pattern y = n*x^p)

Usage

Generating Test Data

# Syntax: generator [num_points] [factor] [power]
# Creates test.data with y = factor*x^power pattern
./generator 100 2 2   # Creates 100 points following y = 2x²

Creating a Graph

# Syntax: grapher [data_file] [width] [height] [x_scale] [y_scale]
./grapher test.data 800 600 1 1

The output is saved as output.pbm, which can be viewed with most image viewers.

Building

# Compile the grapher
gcc main.c -o grapher

# Compile the generator
gcc generator.c -o generator

Todo

• Implement the draw_line function to connect points
• Add axis lines and labels
• Support for multiple data series

Why Grapher?

In a world of sophisticated graphing libraries and tools, why would anyone use Grapher?

• When the internet is down: No downloading packages or searching Stack Overflow
• Learning purposes: Understand the basics of programmatic visualization
• Minimalism: Sometimes simple is better
• Customization: Easy to modify for your specific needs
• Because sometimes the only tool you have is a C compiler and a dream

License

This project is open source. Feel free to use, modify, and distribute as you wish.

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"Graphs are just pictures for people who don't want to admit they like art." - Unknown