def _zoom(a_lo, a_hi, phi_lo, phi_hi, derphi_lo,
          phi, derphi, phi0, derphi0, c1, c2):

    maxiter = 10
    i = 0
    delta1 = 0.2  # cubic interpolant check
    delta2 = 0.1  # quadratic interpolant check
    phi_rec = phi0
    a_rec = 0
    while True:
        # interpolate to find a trial step length between a_lo and
        # a_hi Need to choose interpolation here.  Use cubic
        # interpolation and then if the result is within delta *
        # dalpha or outside of the interval bounded by a_lo or a_hi
        # then use quadratic interpolation, if the result is still too
        # close, then use bisection

        dalpha = a_hi - a_lo
        if dalpha < 0:
            a, b = a_hi, a_lo
        else:
            a, b = a_lo, a_hi

        # minimizer of cubic interpolant
        # (uses phi_lo, derphi_lo, phi_hi, and the most recent value of phi)
        #
        # if the result is too close to the end points (or out of the
        # interval) then use quadratic interpolation with phi_lo,
        # derphi_lo and phi_hi if the result is stil too close to the
        # end points (or out of the interval) then use bisection

        if (i > 0):
            cchk = delta1 * dalpha
            a_j = _cubicmin(a_lo, phi_lo, derphi_lo, a_hi, phi_hi,
                            a_rec, phi_rec)
        if (i == 0) or (a_j is None) or (a_j > b - cchk) or (a_j < a + cchk):
            qchk = delta2 * dalpha
            a_j = _quadmin(a_lo, phi_lo, derphi_lo, a_hi, phi_hi)
            if (a_j is None) or (a_j > b-qchk) or (a_j < a+qchk):
                a_j = a_lo + 0.5*dalpha

        # Check new value of a_j

        phi_aj = phi(a_j)
        if (phi_aj > phi0 + c1*a_j*derphi0) or (phi_aj >= phi_lo):
            phi_rec = phi_hi
            a_rec = a_hi
            a_hi = a_j
            phi_hi = phi_aj
        else:
            derphi_aj = derphi(a_j)
            if abs(derphi_aj) <= -c2*derphi0:
                a_star = a_j
                val_star = phi_aj
                valprime_star = derphi_aj
                break
            if derphi_aj*(a_hi - a_lo) >= 0:
                phi_rec = phi_hi
                a_rec = a_hi
                a_hi = a_lo
                phi_hi = phi_lo
            else:
                phi_rec = phi_lo
                a_rec = a_lo
            a_lo = a_j
            phi_lo = phi_aj
            derphi_lo = derphi_aj
        i += 1
        if (i > maxiter):
            # Failed to find a conforming step size
            a_star = None
            val_star = None
            valprime_star = None
            break
    return a_star, val_star, valprime_star


#------------------------------------------------------------------------------
# Armijo line and scalar searches
#------------------------------------------------------------------------------
dictorsetmaker : test dosm_comma_list COMMA
dataset/ETHPy150Open scipy/scipy/scipy/optimize/linesearch.py/_zoom--crossover with--dataset/ETHPy150Open nucleic/enaml/enaml/core/parser.py/p_dictorsetmaker9