Animating the Indian National Flag in Python — A Tribute to the Tiranga 🇮🇳

Jai Hind! As we approach August 15, India's Independence Day, let’s celebrate by paying homage to the Tiranga — the Indian National Flag — using code! In this tutorial, you’ll learn how to generate a beautiful waving tricolour flag using Python and matplotlib.

🇮🇳 About the Tiranga

The Indian National Flag, adopted on July 22, 1947, is a horizontal tricolour of saffron at the top, white in the middle, and green at the bottom, with the Ashoka Chakra — a 24-spoked navy-blue wheel — in the center.

The flag’s design and proportions are governed by the Bureau of Indian Standards (IS 1:1968). Let’s stick closely to these standards while animating.

📐 Official Specifications

• Flag Ratio: 3:2 (length to height)
• Each stripe: Equal height (i.e., 1/3rd of flag height)
• Ashoka Chakra: 24 spokes, navy blue, radius = 3/4 of the white band’s height

💻 Python Animation of the Flag

🎨 Steps We Will Follow

1. Draw three equal horizontal bands of saffron, white, and green
2. Draw a navy-blue Ashoka Chakra centered on the white band
3. Apply a horizontal sine wave effect to simulate waving
4. Animate with matplotlib.animation

📦 Requirements

pip install matplotlib numpy

🧑‍💻 Full Working Code

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as patches
import matplotlib.animation as animation

# Flag dimensions (aspect ratio 3:2)
width = 3.0
height = 2.0
stripe_height = height / 3

fig, ax = plt.subplots(figsize=(9, 6))
ax.set_xlim(0, width)
ax.set_ylim(0, height)
ax.set_aspect('equal')
ax.axis('off')

def draw_chakra(ax, center_x, center_y, radius):
    chakra = plt.Circle((center_x, center_y), radius, color='navy', fill=False, linewidth=2)
    ax.add_patch(chakra)
    for i in range(24):
        angle = 2 * np.pi * i / 24
        x_end = center_x + radius * np.cos(angle)
        y_end = center_y + radius * np.sin(angle)
        ax.plot([center_x, x_end], [center_y, y_end], color='navy', linewidth=1)

def update(frame):
    ax.clear()
    ax.set_xlim(0, width)
    ax.set_ylim(0, height)
    ax.set_aspect('equal')
    ax.axis('off')

    wave_offset = frame / 10.0
    x = np.linspace(0, width, 300)

    stripe_colors = ['#FF9933', 'white', '#138808']

    for i, color in enumerate(stripe_colors):
        y_base = height - (i + 1) * stripe_height
        y_wave = y_base + 0.05 * np.sin(2 * np.pi * x / width + wave_offset + i)
        ax.fill_between(x, y_wave, y_wave + stripe_height, color=color, zorder=0)

    cx = width / 2
    cy = stripe_height + stripe_height / 2
    cy += 0.05 * np.sin(2 * np.pi * cx / width + wave_offset + 1)
    draw_chakra(ax, cx, cy, 0.3)

ani = animation.FuncAnimation(fig, update, frames=200, interval=50)
plt.show()

🎆 A Digital Salute

With just a few lines of code, we’ve created a digital version of the Indian national flag that waves with pride and grace. Customize it further, export as a GIF, or even sync it with music for a true patriotic vibe.

Vande Mataram! Jai Hind! 🇮🇳