Correlation Matrix or Covariance Matrix in PCA
6316
PCA on correlation or covariance?
123573
Is a sample covariance matrix always symmetric and positive definite?
103877
The advantages and disadvantages of using Kaiser Rule to select the number of principal components
55847
PCA demeaning the data
24459
Why does correlation matrix need to be positive semi-definite and what does it mean to be or not to be positive semi-definite?
143724
Is it possible to use kernel PCA for feature selection?
48101
Correlation and skewness
45832
What is the relation between k-means clustering and PCA?
26181
Using principal component analysis (PCA) for feature selection
116362
Is PCA unstable under multicollinearity?
18487
Why are there only $n-1$ principal components for $n$ data if the number of dimensions is $\ge n$?
63042
What are the differences between Factor Analysis and Principal Component Analysis?
9286
Questions on PCA: when are PCs independent? why is PCA sensitive to scaling? why are PCs constrained to be orthogonal?
6206
How does centering make a difference in PCA (for SVD and eigen decomposition)?
157062
Dimensionality reduction (SVD or PCA) on a large, sparse matrix
82178
Does it make sense to combine PCA and LDA?
70917
What's the difference between principal component analysis and multidimensional scaling?