Analysis And Rela... | Nonlinear Principal Component
Nonlinear transfer functions (like hyperbolic tangents) in the hidden layers empower the network to characterize arbitrary continuous curves. 2. Principal Curves and Manifolds
Traditional PCA finds the lower-dimensional hyperplane that minimizes the sum of squared orthogonal deviations from the dataset. In contrast, NLPCA maps the data to a lower-dimensional curved surface. Nonlinear Principal Component Analysis and Rela...
Because the bottleneck layer contains fewer nodes than the input or output layers, the network is forced to compress the data. The values extracted at this bottleneck represent the nonlinear principal component scores. In contrast, NLPCA maps the data to a
Instead of relying on iterative neural network training, Kernel PCA applies the "kernel trick" widely utilized in Support Vector Machines. It maps the original data into a highly dimensional (often infinite) feature space where the previously nonlinear relationships become linear. Standard linear PCA is then performed in this new space. ⚖️ A Direct Comparison: Linear vs. Nonlinear PCA Instead of relying on iterative neural network training,