(Choose 2 answers)
Which of the following statements are true? Check all that apply.
A. Given an input x is a n-dimensional vector, PCA compresses it to a lowerdimensional vector z.
B. Even if all the input features are on very similar scales, we should still perform mean normalization (so th each feature has zero mean) before running PCA.
C. PCA can be used only to reduce the dimensionality of data by 1 (such as 3D to 2D, or 2D to 1D).
D. PCA is susceptible to local optima; trying multiple random initializations may help.
E24
