quadratic-plotter/README.md

Quadratic Equation Plotter

A Python GUI application for plotting quadratic equations using Tkinter and Matplotlib.

Features

• Plot any quadratic equation in the form: y = ax² + bx + c
• Adjustable X-axis range
• Visualize vertex and roots (when they exist)
• Save plots in multiple formats (PNG, JPEG, PDF, SVG)
• Interactive matplotlib navigation toolbar (zoom, pan, save)
• Clean, user-friendly interface

Requirements

• Python 3.6 or higher
• NumPy
• Matplotlib

Installation

1. Install Python dependencies:

pip install -r requirements.txt

Or install manually:

pip install numpy matplotlib

Usage

Run the application:

python quadratic_plotter.py

Interface Components:

1. Coefficients Input:

   • Enter values for a, b, and c
   • Default: a=1, b=0, c=0 (plots y = x²)

2. X-axis Range:

   • Set the range of x-values to plot
   • Default: -10 to 10

3. Buttons:

   • Plot Quadratic: Generate the plot with current parameters
   • Save Plot: Save the current plot to a file
   • Clear Plot: Clear the current plot

4. Plot Area:

   • Interactive matplotlib plot with zoom and pan capabilities
   • Vertex shown as red dot (for a ≠ 0)
   • Roots shown as green dots (when real roots exist)
   • Legend showing equation and key points

Example Plots

1. Standard Parabola: a=1, b=0, c=0
2. Shifted Parabola: a=1, b=-2, c=1
3. Downward Parabola: a=-1, b=0, c=4
4. Linear Function: a=0, b=2, c=1 (plots a straight line)

Features in Detail

Vertex Calculation

The vertex of the parabola is calculated using:

x_vertex = -b / (2a)
y_vertex = a(x_vertex)² + b(x_vertex) + c

Roots Calculation

Real roots are calculated using the quadratic formula:

x = [-b ± √(b² - 4ac)] / (2a)

Plot Customization

• Blue line: Quadratic curve
• Red dot: Vertex of parabola
• Green dots: Real roots (x-intercepts)
• Grid lines for easy reference
• Axes lines through origin

Error Handling

The application includes error handling for:

• Invalid numeric input
• X-min greater than X-max
• File save errors
• Missing dependencies

License

This project is open source and available for educational and personal use.

Troubleshooting

If you encounter issues:

1. Missing dependencies: Ensure all packages are installed
2. GUI not showing: Check if Tkinter is installed (usually bundled with Python)
3. Plot not updating: Verify all input fields contain valid numbers
4. ImportError: "NavigationToolbar2Tk" is not exported: This application includes compatibility code for different matplotlib versions. If you see this error, update matplotlib to version 3.4 or later:

   pip install --upgrade matplotlib
   

   The code will automatically try multiple import locations for backward compatibility.

Screenshot

Note: Add your own screenshot after running the application

GitHub Repository Setup

This project is already initialized as a Git repository. To push it to a private GitHub repository:

Option 1: Using GitHub CLI (Recommended)

1. Install GitHub CLI if not already installed:

   # On Ubuntu/Debian
   sudo apt install gh
   
   # On macOS
   brew install gh
   

2. Authenticate with GitHub:

   gh auth login
   

3. Create a new private repository:

   gh repo create quadratic-plotter --private --source=. --remote=origin --push
   

Option 2: Manual Setup

1. Create a new private repository on GitHub.com:

   • Repository name: quadratic-plotter (or your preferred name)
   • Select "Private"
   • Do NOT initialize with README, .gitignore, or license

2. Add the remote and push:

   git remote add origin https://github.com/YOUR_USERNAME/quadratic-plotter.git
   git branch -M main
   git push -u origin main
   

Option 3: Using SSH

If you prefer SSH authentication:

1. Add your SSH key to GitHub
2. Use SSH URL:

   git remote add origin git@github.com:YOUR_USERNAME/quadratic-plotter.git
   git branch -M main
   git push -u origin main
   

Verification

After pushing, verify your repository:

git log --oneline
git remote -v
git status