Accord.Tests.Math.FiniteDifferencesTest.ComputeTest2 C# (CSharp) Method

        public void ComputeTest2()
        {
            // Create a simple function with two parameters: f(x,y) = x² + y
            Func<double[], double> function = x => Math.Pow(x[0], 2) + x[1];

            // The gradient w.r.t to x should be 2x,
            // the gradient w.r.t to y should be  1


            // Create a new finite differences calculator
            var calculator = new FiniteDifferences(2, function);

            // Evaluate the gradient function at the point (2, -1)
            double[] result = calculator.Compute(2, -1); // answer is (4, 1)

            Assert.AreEqual(4, result[0], 1e-10);
            Assert.AreEqual(1, result[1], 1e-10);
            Assert.IsFalse(Double.IsNaN(result[0]));
            Assert.IsFalse(Double.IsNaN(result[1]));
        }