Smartphone Battery Life ANOVA

import matplotlib.pyplot as plt
import numpy as np
import scipy.stats as stats

np.random.seed(2020)

# Screen-on time in hours
iphone = np.random.normal(8.5, 1.2, 100)
samsung = np.random.normal(9.2, 1.5, 100)
pixel = np.random.normal(7.8, 1.3, 100)
oneplus = np.random.normal(10.5, 1.8, 100)

F_stat, p_value = stats.f_oneway(iphone, samsung, pixel, oneplus)

fig, ax = plt.subplots(figsize=(12, 7), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

colors = ['#374151', '#4927F5', '#F5B027', '#C82909']

parts = ax.violinplot([iphone, samsung, pixel, oneplus], 
                       positions=[1, 2, 3, 4], showmeans=True, showmedians=True, widths=0.7)

for i, pc in enumerate(parts['bodies']):
    pc.set_facecolor(colors[i])
    pc.set_alpha(0.6)
    pc.set_edgecolor(colors[i])
    pc.set_linewidth(2)

parts['cmeans'].set_color('#F5276C')
parts['cmeans'].set_linewidth(2.5)
parts['cmedians'].set_color('#1f2937')
for partname in ['cbars', 'cmins', 'cmaxes']:
    parts[partname].set_color('#9ca3af')

# All-day threshold
ax.axhline(y=8, color='#22c55e', linestyle='--', alpha=0.7, linewidth=1.5)
ax.text(4.45, 8, 'All-day', fontsize=8, color='#22c55e', va='center')

labels = ['iPhone 15 Pro', 'Samsung S24', 'Pixel 8 Pro', 'OnePlus 12']
means = [iphone.mean(), samsung.mean(), pixel.mean(), oneplus.mean()]

# Battery and charging at bottom
capacities = ['3274mAh', '4900mAh', '5050mAh', '5400mAh']
charge_speeds = ['27W', '45W', '30W', '100W']
for i, (cap, speed, color) in enumerate(zip(capacities, charge_speeds, colors)):
    ax.text(i+1, 3.5, f'{cap} | {speed}', ha='center', fontsize=8, color=color)

# Stats at top
stats_text = f"ANOVA: F={F_stat:.2f}, p={p_value:.2e} | Best: OnePlus 12 (μ={oneplus.mean():.1f}h)"
bbox = dict(boxstyle="round,pad=0.3", facecolor='#fef3c7', edgecolor='#F5B027', lw=2)
ax.text(0.5, 1.02, stats_text, transform=ax.transAxes, fontsize=9, color='#1f2937',
        ha='center', va='bottom', fontfamily='monospace', bbox=bbox)

ax.set_xticks([1, 2, 3, 4])
ax.set_xticklabels(labels, fontsize=10, color='#1f2937')
ax.set_ylabel('Screen-On Time (Hours)', fontsize=12, color='#1f2937', fontweight='500')
ax.set_title('Flagship Smartphone Battery Endurance\n2024 Video Playback Test', 
             fontsize=14, color='#1f2937', fontweight='bold', pad=25)

ax.tick_params(colors='#374151')
for spine in ax.spines.values():
    spine.set_color('#e5e7eb')
ax.yaxis.grid(True, color='#f3f4f6', linewidth=0.8)
ax.set_axisbelow(True)
ax.set_ylim(3, 16)

plt.tight_layout()
plt.show()