PCA on train and test datasets: do I need to merge them?
2632
PCA and the train/test split
116362
Is PCA unstable under multicollinearity?
84446
How to project a new vector onto PCA space?
154899
Is it valid to perform PCA if Kaiser-Meyer-Olkin (KMO) index is very low?
70245
Why is the eigenvector in PCA taken to be unit norm?
24814
Is PCA still done via the eigendecomposition of the covariance matrix when dimensionality is larger than the number of observations?
26181
Using principal component analysis (PCA) for feature selection
74282
Can I use PCA (or should I use regression) for testing the effect of multiple variables on one dependent variable?
55847
PCA demeaning the data
67179
AUC and class imbalance in training/test dataset
156944
Is there a test/technique/method for comparing principal components decompositions between samples?
29381
How to perform dimensionality reduction with PCA in R
67557
Imputation of missing values for PCA
139690
Which variables should I transform, center, and/or standardize in my data for Principal Component Analysis?
116179
Is principal component regression (PCR) using principal component scores for regression?
126726
PCA, LDA, CCA, and PLS
71090
Scikit learn - fit_transform on the test set