def line_search(self, r, g, e, previously_reset_hessian):
self.p = self.p.ravel()
p_size = np.sqrt((self.p**2).sum())
if p_size <= np.sqrt(len(self.atoms) * 1e-10):
self.p /= (p_size / np.sqrt(len(self.atoms) * 1e-10))
g = g.ravel()
r = r.ravel()
if self.use_armijo:
try:
# CO: modified call to ls.run
# TODO: pass also the old slope to the linesearch
# so that the RumPath can extract a better starting guess?
# alternatively: we can adjust the rotation_factors
# out using some extrapolation tricks?
ls = LineSearchArmijo(self.func, c1=self.c1, tol=1e-14)
step, func_val, no_update = ls.run(
r,
self.p,
a_min=self.a_min,
func_start=e,
func_prime_start=g,
func_old=self.e0,
rigid_units=self.rigid_units,
rotation_factors=self.rotation_factors,
maxstep=self.maxstep)
self.e0 = e
self.e1 = func_val
self.alpha_k = step
except (ValueError, RuntimeError):
if not previously_reset_hessian:
warnings.warn(
'Armijo linesearch failed, resetting Hessian and '
'trying again')
self.reset_hessian()
self.alpha_k = 0.0
else:
raise RuntimeError(
'Armijo linesearch failed after reset of Hessian, '
'aborting')
else:
ls = LineSearch()
self.alpha_k, e, self.e0, self.no_update = \
ls._line_search(self.func, self.fprime, r, self.p, g,
e, self.e0, stpmin=self.a_min,
maxstep=self.maxstep, c1=self.c1,
c2=self.c2, stpmax=50.)
self.e1 = e
if self.alpha_k is None:
raise RuntimeError('Wolff lineSearch failed!')
def line_search(self, r, g, e, previously_reset_hessian):
self.p = self.p.ravel()
p_size = np.sqrt((self.p ** 2).sum())
if p_size <= np.sqrt(len(self.atoms) * 1e-10):
self.p /= (p_size / np.sqrt(len(self.atoms) * 1e-10))
g = g.ravel()
r = r.ravel()
if self.use_armijo:
try:
# CO: modified call to ls.run
# TODO: pass also the old slope to the linesearch
# so that the RumPath can extract a better starting guess?
# alternatively: we can adjust the rotation_factors
# out using some extrapolation tricks?
ls = LineSearchArmijo(self.func, c1=self.c1, tol=1e-14)
step, func_val, no_update = ls.run(
r, self.p, func_start=e,
func_prime_start=g,
func_old=self.e0,
rigid_units=self.rigid_units,
rotation_factors=self.rotation_factors)
self.e0 = e
self.e1 = func_val
self.alpha_k = step
except (ValueError, RuntimeError):
if not previously_reset_hessian:
logger.warning(
'Armijo linesearch failed, resetting Hessian and '
'trying again')
self.reset_hessian()
self.alpha_k = 0.0
else:
logger.error(
'Armijo linesearch failed after reset of Hessian, '
'aborting')
raise
else:
ls = LineSearch()
self.alpha_k, e, self.e0, self.no_update = \
ls._line_search(self.func, self.fprime, r, self.p, g,
e, self.e0,
maxstep=self.maxstep, c1=self.c1,
c2=self.c2, stpmax=50.)
self.e1 = e
if self.alpha_k is None:
raise RuntimeError('Wolff lineSearch failed!')