utils.py 文件源码

def getDistanceFunction(requested_metric):
    """

    This function returns a specified distance function.


    **PARAMETERS**

    :'requested_metric': can be 'hamming', 'eculidean' or any of the functions in https://docs.scipy.org/doc/scipy/reference/spatial.distance.html which only require u and v as input. 

    **OUTPUT**

    returns distance function (as function)

    **HISTORY**

    :Created: Dec 2016, WHT
    :Updated (v0.2.1): Aug 2017, WHT. Changed from distance functions being in misc to using scipy. 

    """

    distance_options = {
        'braycurtis': distance.braycurtis,
        'canberra': distance.canberra,
        'chebyshev': distance.chebyshev,
        'cityblock': distance.cityblock,
        'correlation': distance.correlation,
        'cosine': distance.cosine,
        'euclidean': distance.euclidean,
        'sqeuclidean': distance.sqeuclidean,
        'dice': distance.dice,
        'hamming': distance.hamming,
        'jaccard': distance.jaccard,
        'kulsinski': distance.kulsinski,
        'matching': distance.matching,
        'rogerstanimoto': distance.rogerstanimoto,
        'russellrao': distance.russellrao,
        'sokalmichener': distance.sokalmichener,
        'sokalsneath': distance.sokalsneath,
        'yule': distance.yule,
    }

    if requested_metric in distance_options: 
        return distance_options[requested_metric]
    else:
        raise ValueError('Distance function cannot be found.')