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How does PCA reconstruction work?

Updated May 17, 2026

Short answer

PCA reconstructs original data using inverse transform of components.

Deep explanation

After projection into lower dimensions, PCA can reconstruct approximate original data using selected eigenvectors. Loss occurs due to discarded components.

Real-world example

Image compression and reconstruction.

Common mistakes

  • Expecting perfect reconstruction after dimensionality reduction.

Follow-up questions

  • Why is reconstruction lossy?
  • What reduces error?

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