COSMIT pep8 in cross_val_score
DOC clarify LeavePOut's combinatoric explosion
DOC similar note in narrative docs
DOC More explicit note
Merge pull request #2056 from jnothman/leavepout_clarify

DOC clarify LeavePOut's combinatoric explosion
ENH add latent semantic analysis/sparse truncated SVD

Fixes #1519.
ENH use rnd SVD in TruncatedSVD by default for speed
COSMIT omit unused parameter/return value in svd_flip
TST strengthen TruncatedSVD tests
DOC + MAINT deprecate RandomizedPCA scipy.sparse support
FIX and link LSA clustering example
DOC explain normalization in LSA KMeans example

As requested by @ogrisel.
Merge pull request #1716 from larsmans/truncated-svd

[MRG] add latent semantic analysis/sparse truncated SVD
ENH: Added input checks in confusion_matrix

Also added confusion_matrix to metric tests
Enforce n_folds >= 2 for k-fold cross-validation
Factorize redundant input checks for k-fold cross-validation