def mmf(x, alpha, beta, kappa, delta):
    'Morgan-Mercer-Flodin\n    http://www.pisces-conservation.com/growthhelp/index.html?morgan_mercer_floden.htm\n\n    Parameters\n    ----------\n    x : int\n    alpha : float\n    beta : float\n    kappa : float\n    delta : float\n\n    Returns\n    -------\n    float\n        alpha - (alpha - beta) / (1. + (kappa * x)**delta)\n    '
    return (alpha - ((alpha - beta) / (1.0 + ((kappa * x) ** delta))))
Morgan-Mercer-Flodin
http://www.pisces-conservation.com/growthhelp/index.html?morgan_mercer_floden.htm

Parameters
----------
x : int
alpha : float
beta : float
kappa : float
delta : float

Returns
-------
float
    alpha - (alpha - beta) / (1. + (kappa * x)**delta)
def mmf(x, alpha, beta, kappa, delta):
    'Morgan-Mercer-Flodin\n    http://www.pisces-conservation.com/growthhelp/index.html?morgan_mercer_floden.htm\n\n    Parameters\n    ----------\n    x : int\n    alpha : float\n    beta : float\n    kappa : float\n    delta : float\n\n    Returns\n    -------\n    float\n        alpha - (alpha - beta) / (1. + (kappa * x)**delta)\n    '
    return (alpha - ((alpha - beta) / (1.0 + ((kappa * x) ** delta))))