`scipy.optimize._linesearch:_zoom`

Signature

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

Zoom stage of approximate linesearch satisfying strong Wolfe conditions.

Part of the optimization algorithm in scalar_search_wolfe2.

Implements Algorithm 3.6 (zoom) in Wright and Nocedal, 'Numerical Optimization', 1999, pp. 61.