Fig. 5: Visualization of the feature space using principal component analysis (PCA).
From: Photonic neuromorphic computing using symmetry-protected zero modes in coupled nanolaser arrays
a Iris dataset showing that Setosa is clearly separated from the rests, while Versicolor and Virginica exhibit some overlap. The dashed line represents the non-convex boundary. b and c present the handwritten digits dataset, illustrating two clusters representing digits “0” and “1” at different image resolutions. The decreasing dimensionality (from 8 × 8 to 2 × 2) leads to significant overlap between classes.
