def tri(N, M=None, k=0, dtype=float):
    if M is None: M = N
    m = greater_equal(subtract.outer(arange(N), arange(M)),-k)
    return m.astype(dtype)
Do nothing and return the estimator unchanged
dataset/ETHPy150Open nipy/nitime/nitime/index_utils.py/tri--crossover with--dataset/ETHPy150Open scikit-learn/scikit-learn/sklearn/preprocessing/data.py/Normalizer.fit