6.11.1. scikits.learn.cross_val.LeaveOneOut¶
- class scikits.learn.cross_val.LeaveOneOut(n)¶
Leave-One-Out cross validation iterator
Provides train/test indexes to split data in train test sets
- __init__(n)¶
Leave-One-Out cross validation iterator
Provides train/test indexes to split data in train test sets
Parameters : n: int :
Total number of elements
Examples
>>> from scikits.learn import cross_val >>> X = np.array([[1, 2], [3, 4]]) >>> y = np.array([1, 2]) >>> loo = cross_val.LeaveOneOut(2) >>> len(loo) 2 >>> print loo scikits.learn.cross_val.LeaveOneOut(n=2) >>> for train_index, test_index in loo: ... print "TRAIN:", train_index, "TEST:", test_index ... X_train, X_test = X[train_index], X[test_index] ... y_train, y_test = y[train_index], y[test_index] ... print X_train, X_test, y_train, y_test TRAIN: [False True] TEST: [ True False] [[3 4]] [[1 2]] [2] [1] TRAIN: [ True False] TEST: [False True] [[1 2]] [[3 4]] [1] [2]