Code Review Metrics Matrix

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LinearSegmentedColormap

fig, ax = plt.subplots(figsize=(12, 8), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

np.random.seed(42)
reviewers = ['@alice', '@bob', '@carol', '@david', '@emma', '@frank']
repos = ['frontend', 'backend', 'api', 'mobile', 'infra', 'docs', 'tests']
data = np.random.randint(0, 50, (len(reviewers), len(repos)))

# Modern gradient: Slate to Cyan (GitHub-inspired)
colors = ['#f1f5f9', '#94a3b8', '#475569', '#0f172a', '#06b6d4']
cmap = LinearSegmentedColormap.from_list('modern', colors, N=256)

im = ax.imshow(data, cmap=cmap, aspect='auto')

ax.set_xticks(range(len(repos)))
ax.set_yticks(range(len(reviewers)))
ax.set_xticklabels(repos, rotation=45, ha='right', color='#374151', fontsize=10)
ax.set_yticklabels(reviewers, color='#1f2937', fontsize=10, fontweight='500', family='monospace')

for i in range(len(reviewers)):
    for j in range(len(repos)):
        val = data[i, j]
        color = '#ffffff' if val > 25 else '#1f2937'
        ax.text(j, i, f'{val}', ha='center', va='center', color=color, fontsize=11, fontweight='bold')

cbar = plt.colorbar(im, ax=ax, shrink=0.8, pad=0.02)
cbar.set_label('Reviews Completed', color='#1f2937', fontsize=11)
cbar.outline.set_edgecolor('#e5e7eb')
plt.setp(plt.getp(cbar.ax.axes, 'yticklabels'), color='#6b7280')

for spine in ax.spines.values():
    spine.set_color('#e5e7eb')
ax.set_title('Code Review Activity by Repository', fontsize=16, color='#111827', fontweight='bold', pad=15)
plt.tight_layout()
plt.show()