def _update(self):
with self.device:
xp = self.device.xp
Ap = self.A(self.p)
pAp = xp.real(xp.vdot(self.p, Ap)).item()
if pAp <= 0:
self.not_positive_definite = True
return
self.alpha = self.rzold / pAp
util.axpy(self.x, self.alpha, self.p)
if self.iter < self.max_iter - 1:
util.axpy(self.r, -self.alpha, Ap)
if self.P is not None:
z = self.P(self.r)
else:
z = self.r
rznew = xp.real(xp.vdot(self.r, z))
beta = rznew / self.rzold
util.xpay(self.p, beta, z)
self.rzold = rznew
self.resid = self.rzold.item()**0.5
def _update(self):
with self.device:
xp = self.device.xp
Ap = self.A(self.p)
pAp = xp.real(xp.vdot(self.p, Ap))
if pAp == 0:
self.zero_gradient = True
return
self.alpha = self.rzold / pAp
util.axpy(self.x, self.alpha, self.p)
if self.iter < self.max_iter - 1:
util.axpy(self.r, -self.alpha, Ap)
if self.P is not None:
z = self.P(self.r)
else:
z = self.r
rznew = xp.real(xp.vdot(self.r, z))
beta = rznew / self.rzold
util.xpay(self.p, beta, z)
self.rzold = rznew
self.resid = util.asscalar(self.rzold)**0.5
