'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 = [[1, 2], [3, 4]]
>>> y = [1, 2]
>>> loo = cross_val.LeaveOneOut(2)
>>> for train_index, test_index in loo:
...    print "TRAIN:", train_index, "TEST:", test_index
...    X_train, X_test, y_train, y_test = cross_val.split(train_index, test_index, X, y)
...    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]'

def __init__(self, n):

    self.n = n
