235   ap.x().derivatives() = Vector2f::UnitX();  in test_autodiff_vector()
236   ap.y().derivatives() = Vector2f::UnitY();  in test_autodiff_vector()
269   x(0).derivatives().resize(2);  in test_autodiff_hessian()
270   x(0).derivatives().setZero();  in test_autodiff_hessian()
271   x(0).derivatives()(0)= 1;  in test_autodiff_hessian()
272   x(1).derivatives().resize(2);  in test_autodiff_hessian()
273   x(1).derivatives().setZero();  in test_autodiff_hessian()
274   x(1).derivatives()(1)=1;  in test_autodiff_hessian()
277   x(0).value().derivatives() = VectorXd::Unit(2,0);  in test_autodiff_hessian()
278   x(1).value().derivatives() = VectorXd::Unit(2,1);  in test_autodiff_hessian()
282       x(0).derivatives()(idx).derivatives()  = VectorXd::Zero(2);  in test_autodiff_hessian()
283       x(1).derivatives()(idx).derivatives()  = VectorXd::Zero(2);  in test_autodiff_hessian()
288   VERIFY_IS_APPROX(y.value().derivatives()(0), y.derivatives()(0).value());  in test_autodiff_hessian()
289   VERIFY_IS_APPROX(y.value().derivatives()(1), y.derivatives()(1).value());  in test_autodiff_hessian()
290   VERIFY_IS_APPROX(y.value().derivatives()(0), s3*std::cos(s1*s3+s2*s4));  in test_autodiff_hessian()
291   VERIFY_IS_APPROX(y.value().derivatives()(1), s4*std::cos(s1*s3+s2*s4));  in test_autodiff_hessian()
292   VERIFY_IS_APPROX(y.derivatives()(0).derivatives(), -std::sin(s1*s3+s2*s4)*Vector2d(s3*s3,s4*s3));  in test_autodiff_hessian()
293   VERIFY_IS_APPROX(y.derivatives()(1).derivatives(),  -std::sin(s1*s3+s2*s4)*Vector2d(s3*s4,s4*s4));  in test_autodiff_hessian()
296   VERIFY_IS_APPROX(z.derivatives()(0).derivatives(), Vector2d(0,1));  in test_autodiff_hessian()
297   VERIFY_IS_APPROX(z.derivatives()(1).derivatives(), Vector2d(1,0));  in test_autodiff_hessian()