mallows_model.py

from imp import reload
def select_mm(dist_name):
    if dist_name == 'hamming':
        import mallows_hamming as mh
        reload(mh)
        return mh
    elif dist_name == 'kendall':
        import mallows_kendall as mk
        reload(mk)
        return mk
    else:
      raise

import numpy as np



def check_theta_phi(theta, phi):
    """This function automatically converts theta to phi or phi to theta as
    list or float depending on the values and value types given as input
        Parameters
        ----------
        theta: float or list
            Dispersion parameter theta to convert to phi (can be None)
        phi: float or list
            Dispersion parameter phi to convert to theta (can be None)
        Returns
        -------
        tuple
            tuple containing both theta and phi (of list or float type depending on the input type)
    """
    # MANUEL: If we do not give an error, the code continues and who knows what may happen.
    # if not ((phi is None) ^ (theta is None)):
    #     print("Set valid values for phi or theta")
    assert (phi is None) ^ (theta is None), "check_theta_phi: you need to provide either theta or phi but not both"
    # MANUEL: theta_to_phi and phi_to_theta work on numpy arrays, so they will do the right thing independently if the input is a scalar, a list or a numpy array.
    # if phi is None and type(theta)!=list:
    #     phi = theta_to_phi(theta)
    # if theta is None and type(phi)!=list:
    #     theta = phi_to_theta(phi)
    # if phi is None and type(theta)==list:
    #     phi = [theta_to_phi(t) for t in theta]
    # if theta is None and type(phi)==list:
    #     theta = [phi_to_theta(p) for p in phi]
    # return np.array(theta), np.array(phi)
    if phi is None:
        phi = theta_to_phi(theta)
    else:
        theta = phi_to_theta(phi)
    return theta, phi


def theta_to_phi(theta):
    """This functions converts theta dispersion parameter into phi
        Parameters
        ----------
        theta: float
            Real dispersion parameter
        Returns
        -------
        float
            phi real dispersion parameter
    """
    return np.exp(-theta)

def phi_to_theta(phi):
    """This functions converts phi dispersion parameter into theta
        Parameters
        ----------
        phi: float
            Real dispersion parameter
        Returns
        -------
        float
            theta real dispersion parameter
    """
    return -np.log(phi)