ml

PCA Variance

Eigenvalue input or raw data matrix — QR algorithm covariance decomposition, scree plot, cumulative explained variance, components to reach threshold.

Input Mode
Data Matrix (rows = observations, cols = features, max 10×10)
Variance Threshold (%)
PCA Summary
Original dimensions2
Components for 95% variance1
Compression ratio2×
Component Breakdown
PCEigenvalueExplained %Cumulative %
PC11.28496.3%96.32%
PC20.049083.68%100%
Scree Plot
95%PC1PC20%25%50%75%100%
▋ explained variance▋ past threshold—— cumulative--- threshold (95%)
C = XᵀX/(n-1)  ·  QR iteration (20 steps)  ·  explained(i) = λᵢ / Σλ