value_type
Stokhos::KL::OneDExponentialCovarianceFunction<value_type>::
newton(const Func& func, const value_type& a, const value_type& b,
magnitude_type tol, int max_num_its)
{
value_type u = (a+b)/2.0;
value_type f = func.eval(u);
int nit = 0;
while (Teuchos::ScalarTraits<value_type>::magnitude(f) > tol &&
nit < max_num_its) {
std::cout << "u = " << u << " f = " << f << std::endl;
value_type dfdu = func.deriv(u);
u -= f / dfdu;
f = func.eval(u);
++nit;
}
TEUCHOS_TEST_FOR_EXCEPTION(nit >= max_num_its, std::logic_error,
"Nonlinear solver did not converge!" << std::endl);
return u;
}
