def rosmac(y, t=0, r0=0.5, k=10, g0=0.4, h=2, l=0.15, e=0.6):
    """ Rosenzweig-MacArthur predator prey model
    """
    prey, cons = y

    def r(x):
        """ Growth rate """
        return r0*(1 - x/k)

    def g(x):
        """ Grazing rate """
        return g0/(x + h)

    dydt = [r(prey)*prey -g(prey)*prey*cons,
            -l*cons + e*g(prey)*prey*cons]
    return dydt