feature(nb): add a variance difference plot for digit 3 vs 8

2026-04-30 20:04:48 +02:00
parent 0943cfd2bb
commit a375173ec1
2 changed files with 9 additions and 0 deletions
@@ -47,3 +47,12 @@ for i, ax in enumerate(axes.flat):
    ax.axis('off')
 fig.suptitle('NB: Pixel variance per class')
 fig.savefig('naivebayes_digits_variance.png', dpi=150, bbox_inches='tight')
+
+# plot the variance difference between two commonly confused digits like 3 and 8 to see
+# on which pixels nb relies to tell them apart
+plt.figure()
+diff = abs(classifier.var_[3] - classifier.var_[8])
+plt.imshow(diff.reshape(8, 8), cmap='hot')
+plt.title('Variance difference: 3 vs 8')
+plt.colorbar()
+plt.savefig('naivebayes_3v8_variance.png', dpi=150, bbox_inches='tight')