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namespace MathNet.Numerics.UnitTests.LinearAlgebraTests.Single
{
    using System;
    using Distributions;
    using LinearAlgebra.Generic;
    using LinearAlgebra.Single;
    using NUnit.Framework;

    /// <summary>
    /// Abstract class with the common set of matrix tests
    /// </summary>
    public abstract partial class MatrixTests
    {
        /// <summary>
        /// Can multiply with a scalar.
        /// </summary>
        /// <param name="scalar">Scalar value.</param>
        [TestCase(0)]
        [TestCase(1)]
        [TestCase(2.2f)]
        public void CanMultiplyWithScalar(float scalar)
        {
            var matrix = TestMatrices["Singular3x3"];
            var clone = matrix.Clone();
            clone = clone.Multiply(scalar);

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(matrix[i, j] * scalar, clone[i, j]);
                }
            }
        }

        /// <summary>
        /// Can multiply with a vector.
        /// </summary>
        [Test]
        public void CanMultiplyWithVector()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = matrix * x;

            Assert.AreEqual(matrix.RowCount, y.Count);

            for (var i = 0; i < matrix.RowCount; i++)
            {
                var ar = matrix.Row(i);
                var dot = ar * x;
                Assert.AreEqual(dot, y[i]);
            }
        }

        /// <summary>
        /// Can multiply with a vector into a result.
        /// </summary>
        [Test]
        public void CanMultiplyWithVectorIntoResult()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = new DenseVector(3);
            matrix.Multiply(x, y);

            for (var i = 0; i < matrix.RowCount; i++)
            {
                var ar = matrix.Row(i);
                var dot = ar * x;
                Assert.AreEqual(dot, y[i]);
            }
        }

        /// <summary>
        /// Can multiply with a vector into result when updating input argument.
        /// </summary>
        [Test]
        public void CanMultiplyWithVectorIntoResultWhenUpdatingInputArgument()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = x;
            matrix.Multiply(x, x);

            Assert.AreSame(y, x);

            y = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            for (var i = 0; i < matrix.RowCount; i++)
            {
                var ar = matrix.Row(i);
                var dot = ar * y;
                Assert.AreEqual(dot, x[i]);
            }
        }

        /// <summary>
        /// Multiply with vector into result fails when result is <c>null</c>.
        /// </summary>
        [Test]
        public void MultiplyWithVectorIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            Vector<float> y = null;
            Assert.Throws<ArgumentNullException>(() => matrix.Multiply(x, y));
        }

        /// <summary>
        /// Multiply with a vector into too large result throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void MultiplyWithVectorIntoLargerResultThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            Vector<float> y = new DenseVector(4);
            Assert.Throws<ArgumentException>(() => matrix.Multiply(x, y));
        }

        /// <summary>
        /// Can left multiply with a scalar.
        /// </summary>
        /// <param name="scalar">Scalar value.</param>
        [TestCase(0)]
        [TestCase(1)]
        [TestCase(2.2f)]
        public void CanOperatorLeftMultiplyWithScalar(float scalar)
        {
            var matrix = TestMatrices["Singular3x3"];
            var clone = scalar * matrix;

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(scalar * matrix[i, j], clone[i, j]);
                }
            }
        }

        /// <summary>
        /// Can right multiply with a scalar.
        /// </summary>
        /// <param name="scalar">Scalar value.</param>
        [TestCase(0)]
        [TestCase(1)]
        [TestCase(2.2f)]
        public void CanOperatorRightMultiplyWithScalar(float scalar)
        {
            var matrix = TestMatrices["Singular3x3"];
            var clone = matrix * scalar;

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(matrix[i, j] * scalar, clone[i, j]);
                }
            }
        }

        /// <summary>
        /// Can multiply with a scalar into result.
        /// </summary>
        /// <param name="scalar">Scalar value.</param>
        [TestCase(0)]
        [TestCase(1)]
        [TestCase(2.2f)]
        public void CanMultiplyWithScalarIntoResult(float scalar)
        {
            var matrix = TestMatrices["Singular3x3"];
            var result = matrix.Clone();
            matrix.Multiply(scalar, result);

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(matrix[i, j] * scalar, result[i, j]);
                }
            }
        }

        /// <summary>
        /// Multiply with a scalar into <c>null</c> result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void MultiplyWithScalarIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            Matrix<float> result = null;
            Assert.Throws<ArgumentNullException>(() => matrix.Multiply(2.3f, result));
        }

        /// <summary>
        /// Multiply with a scalar when result has more rows throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void MultiplyWithScalarWhenResultHasMoreRowsThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var result = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            Assert.Throws<ArgumentException>(() => matrix.Multiply(2.3f, result));
        }

        /// <summary>
        /// Multiply with a scalar when result has more columns throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void MultiplyWithScalarWhenResultHasMoreColumnsThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var result = CreateMatrix(matrix.RowCount, matrix.ColumnCount + 1);
            Assert.Throws<ArgumentException>(() => matrix.Multiply(2.3f, result));
        }

        /// <summary>
        /// Operator left multiply with a scalar when matrix is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void OperatorLeftMultiplyWithScalarWhenMatrixIsNullThrowsArgumentNullException()
        {
            Matrix<float> matrix = null;
            Assert.Throws<ArgumentNullException>(() => { var result = 2.3f * matrix; });
        }

        /// <summary>
        /// Operator right multiply with a scalar when matrix is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void OperatorRightMultiplyWithScalarWhenMatrixIsNullThrowsArgumentNullException()
        {
            Matrix<float> matrix = null;
            Assert.Throws<ArgumentNullException>(() => { var result = matrix * 2.3f; });
        }

        /// <summary>
        /// Can add a matrix.
        /// </summary>
        /// <param name="mtxA">Matrix A name.</param>
        /// <param name="mtxB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        public void CanAddMatrix(string mtxA, string mtxB)
        {
            var matrixA = TestMatrices[mtxA];
            var matrixB = TestMatrices[mtxB];

            var matrix = matrixA.Clone();
            matrix = matrix.Add(matrixB);
            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(matrix[i, j], matrixA[i, j] + matrixB[i, j]);
                }
            }
        }

        /// <summary>
        /// Adding a matrix when argument is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void AddNullMatrixThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular4x4"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => matrix.Add(other));
        }

        /// <summary>
        /// Adding a matrix with fewer columns throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void AddMatrixWithFewerColumnsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Tall3x2"];
            Assert.Throws<ArgumentOutOfRangeException>(() => matrix.Add(other));
        }

        /// <summary>
        /// Adding a matrix with fewer rows throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void AddMatrixWithFewerRowsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentOutOfRangeException>(() => matrix.Add(other));
        }

        /// <summary>
        /// Add matrices using "+" operator.
        /// </summary>
        /// <param name="mtxA">Matrix A name.</param>
        /// <param name="mtxB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        public void CanAddUsingOperator(string mtxA, string mtxB)
        {
            var matrixA = TestMatrices[mtxA];
            var matrixB = TestMatrices[mtxB];

            var result = matrixA + matrixB;
            for (var i = 0; i < matrixA.RowCount; i++)
            {
                for (var j = 0; j < matrixA.ColumnCount; j++)
                {
                    Assert.AreEqual(result[i, j], matrixA[i, j] + matrixB[i, j]);
                }
            }
        }

        /// <summary>
        /// Add operator when left side is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void AddOperatorWhenLeftSideIsNullThrowsArgumentNullException()
        {
            Matrix<float> matrix = null;
            var other = TestMatrices["Singular3x3"];
            Assert.Throws<ArgumentNullException>(() => { var result = matrix + other; });
        }

        /// <summary>
        /// Add operator when right side is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void AddOperatorWhenRightSideIsNullThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => { var result = matrix + other; });
        }

        /// <summary>
        /// Add operator when right side has fewer columns throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void AddOperatorWhenRightSideHasFewerColumnsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Tall3x2"];
            Assert.Throws<ArgumentOutOfRangeException>(() => { var result = matrix + other; });
        }

        /// <summary>
        /// Add operator when right side has fewer rows throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void AddOperatorWhenRightSideHasFewerRowsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentOutOfRangeException>(() => { var result = matrix + other; });
        }

        /// <summary>
        /// Can subtract a matrix.
        /// </summary>
        /// <param name="mtxA">Matrix A name.</param>
        /// <param name="mtxB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        public void CanSubtractMatrix(string mtxA, string mtxB)
        {
            var matrixA = TestMatrices[mtxA];
            var matrixB = TestMatrices[mtxB];

            var matrix = matrixA.Clone();
            matrix = matrix.Subtract(matrixB);
            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(matrix[i, j], matrixA[i, j] - matrixB[i, j]);
                }
            }
        }

        /// <summary>
        /// Subtract <c>null</c> matrix throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void SubtractNullMatrixThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular4x4"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => matrix.Subtract(other));
        }

        /// <summary>
        /// Subtract a matrix when right side has fewer columns throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void SubtractMatrixWithFewerColumnsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Tall3x2"];
            Assert.Throws<ArgumentOutOfRangeException>(() => matrix.Subtract(other));
        }

        /// <summary>
        /// Subtract a matrix when right side has fewer rows throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void SubtractMatrixWithFewerRowsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentOutOfRangeException>(() => matrix.Subtract(other));
        }

        /// <summary>
        /// Can subtract a matrix using "-" operator.
        /// </summary>
        /// <param name="mtxA">Matrix A name.</param>
        /// <param name="mtxB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        public void CanSubtractUsingOperator(string mtxA, string mtxB)
        {
            var matrixA = TestMatrices[mtxA];
            var matrixB = TestMatrices[mtxB];

            var result = matrixA - matrixB;
            for (var i = 0; i < matrixA.RowCount; i++)
            {
                for (var j = 0; j < matrixA.ColumnCount; j++)
                {
                    Assert.AreEqual(result[i, j], matrixA[i, j] - matrixB[i, j]);
                }
            }
        }

        /// <summary>
        /// Subtract operator when left side is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void SubtractOperatorWhenLeftSideIsNullThrowsArgumentNullException()
        {
            Matrix<float> matrix = null;
            var other = TestMatrices["Singular3x3"];
            Assert.Throws<ArgumentNullException>(() => { var result = matrix - other; });
        }

        /// <summary>
        /// Subtract operator when right side is <c>null</c> throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void SubtractOperatorWhenRightSideIsNullThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => { var result = matrix - other; });
        }

        /// <summary>
        /// Subtract operator when right side has fewer columns throws <c>ArgumentOutOfRangeException</c>
        /// </summary>
        [Test]
        public void SubtractOperatorWhenRightSideHasFewerColumnsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Tall3x2"];
            Assert.Throws<ArgumentOutOfRangeException>(() => { var result = matrix - other; });
        }

        /// <summary>
        /// Subtract operator when right side has fewer rows throws <c>ArgumentOutOfRangeException</c>
        /// </summary>
        [Test]
        public void SubtractOperatorWhenRightSideHasFewerRowsThrowsArgumentOutOfRangeException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentOutOfRangeException>(() => { var result = matrix - other; });
        }

        /// <summary>
        /// Can multiply a matrix with matrix.
        /// </summary>
        /// <param name="nameA">Matrix A name.</param>
        /// <param name="nameB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        [TestCase("Wide2x3", "Square3x3")]
        [TestCase("Wide2x3", "Tall3x2")]
        [TestCase("Tall3x2", "Wide2x3")]
        public void CanMultiplyMatrixWithMatrix(string nameA, string nameB)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameB];
            var matrixC = matrixA * matrixB;

            Assert.AreEqual(matrixC.RowCount, matrixA.RowCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.ColumnCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Row(i) * matrixB.Column(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Can transpose and multiply a matrix with matrix.
        /// </summary>
        /// <param name="nameA">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanTransposeAndMultiplyMatrixWithMatrix(string nameA)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameA];
            var matrixC = matrixA.TransposeAndMultiply(matrixB);

            Assert.AreEqual(matrixC.RowCount, matrixA.RowCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.RowCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Row(i) * matrixB.Row(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Can transpose and multiply a matrix with differing dimensions.
        /// </summary>
        [Test]
        public void CanTransposeAndMultiplyWithDifferingDimensions()
        {
            var matrixA = TestMatrices["Tall3x2"];
            var matrixB = CreateMatrix(5, 2);
            var count = 1;
            for (var row = 0; row < matrixB.RowCount; row++)
            {
                for (var col = 0; col < matrixB.ColumnCount; col++)
                {
                    if (row == col)
                    {
                        matrixB[row, col] = count++;
                    }
                }
            }

            var matrixC = matrixA.TransposeAndMultiply(matrixB);

            Assert.AreEqual(matrixC.RowCount, matrixA.RowCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.RowCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Row(i) * matrixB.Row(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Transpose and multiply a matrix with matrix of incompatible size throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void TransposeAndMultiplyMatrixMatrixWithIncompatibleSizesThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Tall3x2"];
            Assert.Throws<ArgumentException>(() => matrix.TransposeAndMultiply(other));
        }

        /// <summary>
        /// Transpose and multiply a matrix with <c>null</c> matrix throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void TransposeAndMultiplyMatrixWithNullMatrixThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => matrix.TransposeAndMultiply(other));
        }

        /// <summary>
        /// Can transpose and multiply a matrix with matrix into a result matrix.
        /// </summary>
        /// <param name="nameA">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanTransposeAndMultiplyMatrixWithMatrixIntoResult(string nameA)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameA];
            var matrixC = CreateMatrix(matrixA.RowCount, matrixB.RowCount);
            matrixA.TransposeAndMultiply(matrixB, matrixC);

            Assert.AreEqual(matrixC.RowCount, matrixA.RowCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.RowCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Row(i) * matrixB.Row(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Multiply a matrix with incompatible size matrix throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void MultiplyMatrixMatrixWithIncompatibleSizesThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentException>(() => { var result = matrix * other; });
        }

        /// <summary>
        /// Multiply <c>null</c> matrix with matrix throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void MultiplyNullMatrixWithMatrixThrowsArgumentNullException()
        {
            Matrix<float> matrix = null;
            var other = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentNullException>(() => { var result = matrix * other; });
        }

        /// <summary>
        /// Multiply a matrix with <c>null</c> matrix throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void MultiplyMatrixWithNullMatrixThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => { var result = matrix * other; });
        }

        /// <summary>
        /// Can multiply a matrix with matrix into a result matrix.
        /// </summary>
        /// <param name="nameA">Matrix A name.</param>
        /// <param name="nameB">Matrix B name.</param>
        [TestCase("Singular3x3", "Square3x3")]
        [TestCase("Singular4x4", "Square4x4")]
        [TestCase("Wide2x3", "Square3x3")]
        [TestCase("Wide2x3", "Tall3x2")]
        [TestCase("Tall3x2", "Wide2x3")]
        public virtual void CanMultiplyMatrixWithMatrixIntoResult(string nameA, string nameB)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameB];
            var matrixC = CreateMatrix(matrixA.RowCount, matrixB.ColumnCount);
            matrixA.Multiply(matrixB, matrixC);

            Assert.AreEqual(matrixC.RowCount, matrixA.RowCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.ColumnCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Row(i) * matrixB.Column(j), matrixC[i, j], 6);
                }
            }
        }

        /// <summary>
        /// Can multiply transposed matrix with a vector.
        /// </summary>
        [Test]
        public void CanTransposeThisAndMultiplyWithVector()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = matrix.TransposeThisAndMultiply(x);

            Assert.AreEqual(matrix.ColumnCount, y.Count);

            for (var j = 0; j < matrix.ColumnCount; j++)
            {
                var ar = matrix.Column(j);
                var dot = ar * x;
                Assert.AreEqual(dot, y[j]);
            }
        }

        /// <summary>
        /// Can multiply transposed matrix with a vector into a result.
        /// </summary>
        [Test]
        public void CanTransposeThisAndMultiplyWithVectorIntoResult()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = new DenseVector(3);
            matrix.TransposeThisAndMultiply(x, y);

            for (var j = 0; j < matrix.ColumnCount; j++)
            {
                var ar = matrix.Column(j);
                var dot = ar * x;
                Assert.AreEqual(dot, y[j]);
            }
        }

        /// <summary>
        /// Can multiply transposed matrix with a vector into result when updating input argument.
        /// </summary>
        [Test]
        public void CanTransposeThisAndMultiplyWithVectorIntoResultWhenUpdatingInputArgument()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            var y = x;
            matrix.TransposeThisAndMultiply(x, x);

            Assert.AreSame(y, x);

            y = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            for (var j = 0; j < matrix.ColumnCount; j++)
            {
                var ar = matrix.Column(j);
                var dot = ar * y;
                Assert.AreEqual(dot, x[j]);
            }
        }

        /// <summary>
        /// Multiply transposed matrix with vector into result fails when result is <c>null</c>.
        /// </summary>
        [Test]
        public void TransposeThisAndMultiplyWithVectorIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            Vector<float> y = null;
            Assert.Throws<ArgumentNullException>(() => matrix.TransposeThisAndMultiply(x, y));
        }

        /// <summary>
        /// Multiply transposed matrix with a vector into too large result throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void TransposeThisAndMultiplyWithVectorIntoLargerResultThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var x = new DenseVector(new[] { 1.0f, 2.0f, 3.0f });
            Vector<float> y = new DenseVector(4);
            Assert.Throws<ArgumentException>(() => matrix.TransposeThisAndMultiply(x, y));
        }

        /// <summary>
        /// Can multiply transposed matrix with another matrix.
        /// </summary>
        /// <param name="nameA">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanTransposeThisAndMultiplyMatrixWithMatrix(string nameA)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameA];
            var matrixC = matrixA.TransposeThisAndMultiply(matrixB);

            Assert.AreEqual(matrixC.RowCount, matrixA.ColumnCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.ColumnCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Column(i) * matrixB.Column(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Multiply the transpose of matrix with another matrix of incompatible size throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void TransposeThisAndMultiplyMatrixMatrixWithIncompatibleSizesThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = TestMatrices["Singular3x3"];
            Assert.Throws<ArgumentException>(() => matrix.TransposeThisAndMultiply(other));
        }

        /// <summary>
        /// Multiply the transpose of matrix with another matrix <c>null</c> matrix throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void TransposeThisAndMultiplyMatrixWithNullMatrixThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Matrix<float> other = null;
            Assert.Throws<ArgumentNullException>(() => matrix.TransposeThisAndMultiply(other));
        }

        /// <summary>
        /// Multiply transpose of this matrix with another matrix into a result matrix.
        /// </summary>
        /// <param name="nameA">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanTransposeThisAndMultiplyMatrixWithMatrixIntoResult(string nameA)
        {
            var matrixA = TestMatrices[nameA];
            var matrixB = TestMatrices[nameA];
            var matrixC = CreateMatrix(matrixA.ColumnCount, matrixB.ColumnCount);
            matrixA.TransposeThisAndMultiply(matrixB, matrixC);

            Assert.AreEqual(matrixC.RowCount, matrixA.ColumnCount);
            Assert.AreEqual(matrixC.ColumnCount, matrixB.ColumnCount);

            for (var i = 0; i < matrixC.RowCount; i++)
            {
                for (var j = 0; j < matrixC.ColumnCount; j++)
                {
                    AssertHelpers.AlmostEqual(matrixA.Column(i) * matrixB.Column(j), matrixC[i, j], 7);
                }
            }
        }

        /// <summary>
        /// Can negate a matrix.
        /// </summary>
        /// <param name="name">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanNegate(string name)
        {
            var matrix = TestMatrices[name];
            var copy = matrix.Clone();

            copy = copy.Negate();

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(-matrix[i, j], copy[i, j]);
                }
            }
        }

        /// <summary>
        /// Can negate a matrix into a result matrix.
        /// </summary>
        /// <param name="name">Matrix name.</param>
        [TestCase("Singular3x3")]
        [TestCase("Singular4x4")]
        [TestCase("Wide2x3")]
        [TestCase("Wide2x3")]
        [TestCase("Tall3x2")]
        public void CanNegateIntoResult(string name)
        {
            var matrix = TestMatrices[name];
            var copy = matrix.Clone();

            matrix.Negate(copy);

            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    Assert.AreEqual(-matrix[i, j], copy[i, j]);
                }
            }
        }

        /// <summary>
        /// Negate into <c>null</c> result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void NegateIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Singular3x3"];
            Matrix<float> copy = null;
            Assert.Throws<ArgumentNullException>(() => matrix.Negate(copy));
        }

        /// <summary>
        /// Negate into a result matrix with more rows throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void NegateIntoResultWithMoreRowsThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var target = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            Assert.Throws<ArgumentException>(() => matrix.Negate(target));
        }

        /// <summary>
        /// Negate into a result matrix with more rows throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void NegateIntoResultWithMoreColumnsThrowsArgumentException()
        {
            var matrix = TestMatrices["Singular3x3"];
            var target = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            Assert.Throws<ArgumentException>(() => matrix.Negate(target));
        }

        /// <summary>
        /// Can calculate Kronecker product.
        /// </summary>
        [Test]
        public void CanKroneckerProduct()
        {
            var matrixA = TestMatrices["Wide2x3"];
            var matrixB = TestMatrices["Square3x3"];
            var result = CreateMatrix(matrixA.RowCount * matrixB.RowCount, matrixA.ColumnCount * matrixB.ColumnCount);
            matrixA.KroneckerProduct(matrixB, result);
            for (var i = 0; i < matrixA.RowCount; i++)
            {
                for (var j = 0; j < matrixA.ColumnCount; j++)
                {
                    for (var ii = 0; ii < matrixB.RowCount; ii++)
                    {
                        for (var jj = 0; jj < matrixB.ColumnCount; jj++)
                        {
                            Assert.AreEqual(result[(i * matrixB.RowCount) + ii, (j * matrixB.ColumnCount) + jj], matrixA[i, j] * matrixB[ii, jj]);
                        }
                    }
                }
            }
        }

        /// <summary>
        /// Can calculate Kronecker product into a result matrix.
        /// </summary>
        [Test]
        public void CanKroneckerProductIntoResult()
        {
            var matrixA = TestMatrices["Wide2x3"];
            var matrixB = TestMatrices["Square3x3"];
            var result = matrixA.KroneckerProduct(matrixB);
            for (var i = 0; i < matrixA.RowCount; i++)
            {
                for (var j = 0; j < matrixA.ColumnCount; j++)
                {
                    for (var ii = 0; ii < matrixB.RowCount; ii++)
                    {
                        for (var jj = 0; jj < matrixB.ColumnCount; jj++)
                        {
                            Assert.AreEqual(result[(i * matrixB.RowCount) + ii, (j * matrixB.ColumnCount) + jj], matrixA[i, j] * matrixB[ii, jj]);
                        }
                    }
                }
            }
        }

        /// <summary>
        /// Can normalize columns of a matrix.
        /// </summary>
        /// <param name="p">The norm under which to normalize the columns under.</param>
        [TestCase(1)]
        [TestCase(2)]
        public void CanNormalizeColumns(int p)
        {
            var matrix = TestMatrices["Square4x4"];
            var result = matrix.NormalizeColumns(p);
            for (var j = 0; j < result.ColumnCount; j++)
            {
                var col = result.Column(j);
                Assert.AreEqual(1.0f, col.Norm(p), 10e-6f);
            }
        }

        /// <summary>
        /// Normalize columns with wrong parameter throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void NormalizeColumnsWithWrongParameterThrowsArgumentOutOfRangeException()
        {
            Assert.Throws<ArgumentOutOfRangeException>(() => TestMatrices["Square4x4"].NormalizeColumns(-4));
        }

        /// <summary>
        /// Can normalize rows of a matrix.
        /// </summary>
        /// <param name="p">The norm under which to normalize the rows under.</param>
        [TestCase(1)]
        [TestCase(2)]
        public void CanNormalizeRows(int p)
        {
            var matrix = TestMatrices["Square4x4"].NormalizeRows(p);
            for (var i = 0; i < matrix.RowCount; i++)
            {
                var row = matrix.Row(i);
                Assert.AreEqual(1.0f, row.Norm(p), 10e-6f);
            }
        }

        /// <summary>
        /// Normalize rows with wrong parameter throws <c>ArgumentOutOfRangeException</c>.
        /// </summary>
        [Test]
        public void NormalizeRowsWithWrongParameterThrowsArgumentOutOfRangeException()
        {
            Assert.Throws<ArgumentOutOfRangeException>(() => TestMatrices["Square4x4"].NormalizeRows(-4));
        }

        /// <summary>
        /// Can pointwise multiply matrices into a result matrix.
        /// </summary>
        [Test]
        public void CanPointwiseMultiplyIntoResult()
        {
            foreach (var data in TestMatrices.Values)
            {
                var other = data.Clone();
                var result = data.Clone();
                data.PointwiseMultiply(other, result);
                for (var i = 0; i < data.RowCount; i++)
                {
                    for (var j = 0; j < data.ColumnCount; j++)
                    {
                        Assert.AreEqual(data[i, j] * other[i, j], result[i, j]);
                    }
                }

                result = data.PointwiseMultiply(other);
                for (var i = 0; i < data.RowCount; i++)
                {
                    for (var j = 0; j < data.ColumnCount; j++)
                    {
                        Assert.AreEqual(data[i, j] * other[i, j], result[i, j]);
                    }
                }
            }
        }

        /// <summary>
        /// Pointwise multiply <c>null</c> matrices into a result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void PointwiseMultiplyNullIntoResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Matrix<float> other = null;
            var result = matrix.Clone();
            Assert.Throws<ArgumentNullException>(() => matrix.PointwiseMultiply(other, result));
        }

        /// <summary>
        /// Pointwise multiply matrices into <c>null</c> result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void PointwiseMultiplyIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = matrix.Clone();
            Assert.Throws<ArgumentNullException>(() => matrix.PointwiseMultiply(other, null));
        }

        /// <summary>
        /// Pointwise multiply matrices with invalid dimensions into a result throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void PointwiseMultiplyWithInvalidDimensionsIntoResultThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            var result = matrix.Clone();
            Assert.Throws<ArgumentException>(() => matrix.PointwiseMultiply(other, result));
        }

        /// <summary>
        /// Pointwise multiply matrices with invalid result dimensions throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void PointwiseMultiplyWithInvalidResultDimensionsThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = matrix.Clone();
            var result = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            Assert.Throws<ArgumentException>(() => matrix.PointwiseMultiply(other, result));
        }

        /// <summary>
        /// Can pointwise divide matrices into a result matrix.
        /// </summary>
        [Test]
        public virtual void CanPointwiseDivideIntoResult()
        {
            var data = TestMatrices["Singular3x3"];
            var other = data.Clone();
            var result = data.Clone();
            data.PointwiseDivide(other, result);
            for (var i = 0; i < data.RowCount; i++)
            {
                for (var j = 0; j < data.ColumnCount; j++)
                {
                    Assert.AreEqual(data[i, j] / other[i, j], result[i, j]);
                }
            }

            result = data.PointwiseDivide(other);
            for (var i = 0; i < data.RowCount; i++)
            {
                for (var j = 0; j < data.ColumnCount; j++)
                {
                    Assert.AreEqual(data[i, j] / other[i, j], result[i, j]);
                }
            }
        }

        /// <summary>
        /// Pointwise divide <c>null</c> matrices into a result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void PointwiseDivideNullIntoResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Matrix<float> other = null;
            var result = matrix.Clone();
            Assert.Throws<ArgumentNullException>(() => matrix.PointwiseDivide(other, result));
        }

        /// <summary>
        /// Pointwise divide matrices into <c>null</c> result throws <c>ArgumentNullException</c>.
        /// </summary>
        [Test]
        public void PointwiseDivideIntoNullResultThrowsArgumentNullException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = matrix.Clone();
            Assert.Throws<ArgumentNullException>(() => matrix.PointwiseDivide(other, null));
        }

        /// <summary>
        /// Pointwise divide matrices with invalid dimensions into a result throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void PointwiseDivideWithInvalidDimensionsIntoResultThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            var result = matrix.Clone();
            Assert.Throws<ArgumentException>(() => matrix.PointwiseDivide(other, result));
        }

        /// <summary>
        /// Pointwise divide matrices with invalid result dimensions throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void PointwiseDivideWithInvalidResultDimensionsThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            var other = matrix.Clone();
            var result = CreateMatrix(matrix.RowCount + 1, matrix.ColumnCount);
            Assert.Throws<ArgumentException>(() => matrix.PointwiseDivide(other, result));
        }

        /// <summary>
        /// Create random matrix with non-positive number of rows throw <c>ArgumentException</c>.
        /// </summary>
        /// <param name="numberOfRows">Number of rows.</param>
        [TestCase(0)]
        [TestCase(-2)]
        public void RandomWithNonPositiveNumberOfRowsThrowsArgumentException(int numberOfRows)
        {
            var matrix = CreateMatrix(2, 3);
            Assert.Throws<ArgumentException>(() => matrix.Random(numberOfRows, 4, new ContinuousUniform()));
            Assert.Throws<ArgumentException>(() => matrix.Random(numberOfRows, 4, new DiscreteUniform(0, 2)));
        }

        /// <summary>
        /// Can trace.
        /// </summary>
        [Test]
        public void CanTrace()
        {
            var matrix = TestMatrices["Square3x3"];
            var trace = matrix.Trace();
            Assert.AreEqual(6.6f, trace);
        }

        /// <summary>
        /// Trace of non-square matrix throws <c>ArgumentException</c>.
        /// </summary>
        [Test]
        public void TraceOfNonSquareMatrixThrowsArgumentException()
        {
            var matrix = TestMatrices["Wide2x3"];
            Assert.Throws<ArgumentException>(() => matrix.Trace());
        }

        /// <summary>
        /// Can compute the modules of each element of vector.
        /// </summary>
        [Test]
        public void CanComputeModulus()
        {
            var matrix = TestMatrices["Square3x3"];
            var mod = matrix.Modulus(3.2f);
            for (var row = 0; row < matrix.RowCount; row++)
            {
                for (var column = 0; column < matrix.ColumnCount; column++)
                {
                    AssertHelpers.AlmostEqual(matrix[row, column] % 3.2f, mod[row, column], 7);
                }
            }
        }

        /// <summary>
        /// Can compute the modules of each element of vector using a result vector.
        /// </summary>
        [Test]
        public void CanComputeModulusUsingResultVector()
        {
            var matrix = TestMatrices["Square3x3"];
            var mod = CreateMatrix(matrix.RowCount, matrix.ColumnCount);
            matrix.Modulus(3.2f, mod);

            for (var row = 0; row < matrix.RowCount; row++)
            {
                for (var column = 0; column < matrix.ColumnCount; column++)
                {
                    AssertHelpers.AlmostEqual(matrix[row, column] % 3.2f, mod[row, column], 7);
                }
            }
        }

        /// <summary>
        /// Can compute the modules of each element of vector using a result vector.
        /// </summary>
        [Test]
        public void CanComputeModulusUsingSameResultVector()
        {
            var matrix = TestMatrices["Square3x3"].Clone();
            matrix.Modulus(3.2f, matrix);
            var data = TestMatrices["Square3x3"];

            for (var row = 0; row < matrix.RowCount; row++)
            {
                for (var column = 0; column < matrix.ColumnCount; column++)
                {
                    AssertHelpers.AlmostEqual(data[row, column] % 3.2f, matrix[row, column], 7);
                }
            }
        }

        /// <summary>
        /// Can compute the modules of each element of vector using the operator %.
        /// </summary>
        [Test]
        public void CanComputeModulusUsingOperator()
        {
            var matrix = TestMatrices["Square3x3"];
            var mod = matrix % 3.2f;
            for (var row = 0; row < matrix.RowCount; row++)
            {
                for (var column = 0; column < matrix.ColumnCount; column++)
                {
                    AssertHelpers.AlmostEqual(matrix[row, column] % 3.2f, mod[row, column], 7);
                }
            }
        }
    }
}