def __init__(self, name, host='127.0.0.1', port=27017):
        self.name = name
        self.host = host
        self.port = port
def f(i):
        start = W[i]
        extent = W[i + 1] - W[i]
        rv = te.reduce_axis((0, extent))
        return te.sum(X[rv + start], axis=rv)