Fix Wolfe condition with proper signs

            Vector gradientN;

            Vector xvalN;

            Scalar fvalN;

            Scalar gradientDot = gradient.dot(gradient);

            Scalar stepGrad = -gradient.dot(gradient);

            bool armijoCondition = false;

            bool wolfeCondition = false;

                xvalN = xval - stepSize * gradient;

                fvalN = objective_(xvalN, gradientN);

                armijoCondition = fvalN <= fval - c1_ * stepSize * gradientDot;

                wolfeCondition = gradient.dot(gradientN) <= c2_ * gradientDot;

                armijoCondition = fvalN <= fval + c1_ * stepSize * stepGrad;

                wolfeCondition = -gradient.dot(gradientN) >= c2_ * stepGrad;

                ++iterations;

            }