svm.py 文件源码

def _convert_to_svm_node_array(x):
    """ convert a sequence or mapping to an svm_node array """
    import operator

    # Find non zero elements
    iter_range = []
    if type(x) == dict:
        for k, v in x.iteritems():
            # all zeros kept due to the precomputed kernel; no good solution yet
            #           if v != 0:
            iter_range.append(k)
    elif operator.isSequenceType(x):
        for j in range(len(x)):
            #           if x[j] != 0:
            iter_range.append(j)
    else:
        raise TypeError, "data must be a mapping or a sequence"

    iter_range.sort()
    data = svmc.svm_node_array(len(iter_range) + 1)
    svmc.svm_node_array_set(data, len(iter_range), -1, 0)

    j = 0
    for k in iter_range:
        svmc.svm_node_array_set(data, j, k, x[k])
        j = j + 1
    return data