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C# Matrix.GetArrayCopy方法代码示例

本文整理汇总了C#中System.Matrix.GetArrayCopy方法的典型用法代码示例。如果您正苦于以下问题:C# Matrix.GetArrayCopy方法的具体用法?C# Matrix.GetArrayCopy怎么用?C# Matrix.GetArrayCopy使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在System.Matrix的用法示例。


在下文中一共展示了Matrix.GetArrayCopy方法的5个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: QRDecomposition

        /// <summary>
        /// QR Decomposition, computed by Householder reflections.
        /// </summary>
        /// <param name="A">Structure to access R and the Householder vectors and compute Q.</param>
        public QRDecomposition(Matrix A)
        {
            // Initialize.
            QR = A.GetArrayCopy();
            m = A.Rows;
            n = A.Cols;
            Rdiag = new double[n];

            // Main loop.
            for (int k = 0; k < n; k++)
            {
                // Compute 2-norm of k-th column without under/overflow.
                double nrm = 0;
                for (int i = k; i < m; i++)
                {
                    nrm = EncogMath.Hypot(nrm, QR[i][k]);
                }

                if (nrm != 0.0)
                {
                    // Form k-th Householder vector.
                    if (QR[k][k] < 0)
                    {
                        nrm = -nrm;
                    }
                    for (int i = k; i < m; i++)
                    {
                        QR[i][k] /= nrm;
                    }
                    QR[k][k] += 1.0;

                    // Apply transformation to remaining columns.
                    for (int j = k + 1; j < n; j++)
                    {
                        double s = 0.0;
                        for (int i = k; i < m; i++)
                        {
                            s += QR[i][k] * QR[i][j];
                        }
                        s = -s / QR[k][k];
                        for (int i = k; i < m; i++)
                        {
                            QR[i][j] += s * QR[i][k];
                        }
                    }
                }
                Rdiag[k] = -nrm;
            }
        }
开发者ID:OperatorOverload,项目名称:encog-cs,代码行数:53,代码来源:QRDecomposition.cs

示例2: Solve

        /// <summary>
        /// Least squares solution of A*X = B
        /// </summary>
        /// <param name="B">A Matrix with as many rows as A and any number of columns.</param>
        /// <returns>that minimizes the two norm of Q*R*X-B.</returns>
        public Matrix Solve(Matrix B)
        {
            if (B.Rows != m)
            {
                throw new MatrixError(
                        "Matrix row dimensions must agree.");
            }
            if (!this.IsFullRank() )
            {
                throw new MatrixError("Matrix is rank deficient.");
            }

            // Copy right hand side
            int nx = B.Cols;
            double[][] X = B.GetArrayCopy();

            // Compute Y = transpose(Q)*B
            for (int k = 0; k < n; k++)
            {
                for (int j = 0; j < nx; j++)
                {
                    double s = 0.0;
                    for (int i = k; i < m; i++)
                    {
                        s += QR[i][k] * X[i][j];
                    }
                    s = -s / QR[k][k];
                    for (int i = k; i < m; i++)
                    {
                        X[i][j] += s * QR[i][k];
                    }
                }
            }
            // Solve R*X = Y;
            for (int k = n - 1; k >= 0; k--)
            {
                for (int j = 0; j < nx; j++)
                {
                    X[k][j] /= Rdiag[k];
                }
                for (int i = 0; i < k; i++)
                {
                    for (int j = 0; j < nx; j++)
                    {
                        X[i][j] -= X[k][j] * QR[i][k];
                    }
                }
            }
            return (new Matrix(X).GetMatrix(0, n - 1, 0, nx - 1));
        }
开发者ID:OperatorOverload,项目名称:encog-cs,代码行数:55,代码来源:QRDecomposition.cs

示例3: SingularValueDecomposition

        /// <summary>
        /// Construct the singular value decomposition
        /// </summary>
        /// <param name="Arg">Rectangular matrix</param>
        public SingularValueDecomposition(Matrix Arg)
        {
            // Derived from LINPACK code.
            // Initialize.
            double[][] A = Arg.GetArrayCopy();
            m = Arg.Rows;
            n = Arg.Cols;

            /*
             * Apparently the failing cases are only a proper subset of (m<n), so
             * let's not throw error. Correct fix to come later? if (m<n) { throw
             * new IllegalArgumentException("Jama SVD only works for m >= n"); }
             */
            int nu = Math.Min(m, n);
            s = new double[Math.Min(m + 1, n)];
            umatrix = EngineArray.AllocateDouble2D(m, nu);
            vmatrix = EngineArray.AllocateDouble2D(n, n);
            var e = new double[n];
            var work = new double[m];
            bool wantu = true;
            bool wantv = true;

            // Reduce A to bidiagonal form, storing the diagonal elements
            // in s and the super-diagonal elements in e.

            int nct = Math.Min(m - 1, n);
            int nrt = Math.Max(0, Math.Min(n - 2, m));
            for (int k = 0; k < Math.Max(nct, nrt); k++)
            {
                if (k < nct)
                {
                    // Compute the transformation for the k-th column and
                    // place the k-th diagonal in s[k].
                    // Compute 2-norm of k-th column without under/overflow.
                    s[k] = 0;
                    for (int i = k; i < m; i++)
                    {
                        s[k] = EncogMath.Hypot(s[k], A[i][k]);
                    }
                    if (s[k] != 0.0)
                    {
                        if (A[k][k] < 0.0)
                        {
                            s[k] = -s[k];
                        }
                        for (int i = k; i < m; i++)
                        {
                            A[i][k] /= s[k];
                        }
                        A[k][k] += 1.0;
                    }
                    s[k] = -s[k];
                }
                for (int j = k + 1; j < n; j++)
                {
                    if ((k < nct) & (s[k] != 0.0))
                    {
                        // Apply the transformation.

                        double t = 0;
                        for (int i = k; i < m; i++)
                        {
                            t += A[i][k]*A[i][j];
                        }
                        t = -t/A[k][k];
                        for (int i = k; i < m; i++)
                        {
                            A[i][j] += t*A[i][k];
                        }
                    }

                    // Place the k-th row of A into e for the
                    // subsequent calculation of the row transformation.

                    e[j] = A[k][j];
                }
                if (wantu & (k < nct))
                {
                    // Place the transformation in U for subsequent back
                    // multiplication.

                    for (int i = k; i < m; i++)
                    {
                        umatrix[i][k] = A[i][k];
                    }
                }
                if (k < nrt)
                {
                    // Compute the k-th row transformation and place the
                    // k-th super-diagonal in e[k].
                    // Compute 2-norm without under/overflow.
                    e[k] = 0;
                    for (int i = k + 1; i < n; i++)
                    {
                        e[k] = EncogMath.Hypot(e[k], e[i]);
                    }
//.........这里部分代码省略.........
开发者ID:CreativelyMe,项目名称:encog-dotnet-core,代码行数:101,代码来源:SingularValueDecomposition.cs

示例4: LUDecomposition

        /// <summary>
        /// LU Decomposition
        /// </summary>
        /// <param name="A">Rectangular matrix</param>
        public LUDecomposition(Matrix A)
        {
            // Use a "left-looking", dot-product, Crout/Doolittle algorithm.

            LU = A.GetArrayCopy();
            m = A.Rows;
            n = A.Cols;
            piv = new int[m];
            for (int i = 0; i < m; i++)
            {
                piv[i] = i;
            }
            pivsign = 1;
            double[] LUrowi;
            double[] LUcolj = new double[m];

            // Outer loop.

            for (int j = 0; j < n; j++)
            {

                // Make a copy of the j-th column to localize references.

                for (int i = 0; i < m; i++)
                {
                    LUcolj[i] = LU[i][j];
                }

                // Apply previous transformations.

                for (int i = 0; i < m; i++)
                {
                    LUrowi = LU[i];

                    // Most of the time is spent in the following dot product.

                    int kmax = Math.Min(i, j);
                    double s = 0.0;
                    for (int k = 0; k < kmax; k++)
                    {
                        s += LUrowi[k] * LUcolj[k];
                    }

                    LUrowi[j] = LUcolj[i] -= s;
                }

                // Find pivot and exchange if necessary.

                int p = j;
                for (int i = j + 1; i < m; i++)
                {
                    if (Math.Abs(LUcolj[i]) > Math.Abs(LUcolj[p]))
                    {
                        p = i;
                    }
                }
                if (p != j)
                {
                    for (int k = 0; k < n; k++)
                    {
                        double t = LU[p][k];
                        LU[p][k] = LU[j][k];
                        LU[j][k] = t;
                    }
                    int temp = piv[p];
                    piv[p] = piv[j];
                    piv[j] = temp;
                    pivsign = -pivsign;
                }

                // Compute multipliers.

                if (j < m & LU[j][j] != 0.0)
                {
                    for (int i = j + 1; i < m; i++)
                    {
                        LU[i][j] /= LU[j][j];
                    }
                }
            }
        }
开发者ID:OperatorOverload,项目名称:encog-cs,代码行数:85,代码来源:LUDecomposition.cs

示例5: Solve

        /// <summary>
        /// Solve A*X = B.
        /// </summary>
        /// <param name="b">A Matrix with as many rows as A and any number of columns.</param>
        /// <returns>X so that L*L'*X = b.</returns>
        public Matrix Solve(Matrix b)
        {
            if (b.Rows != n)
            {
                throw new MatrixError(
                    "Matrix row dimensions must agree.");
            }
            if (!isspd)
            {
                throw new MatrixError(
                    "Matrix is not symmetric positive definite.");
            }

            // Copy right hand side.
            double[][] x = b.GetArrayCopy();
            int nx = b.Cols;

            // Solve L*Y = B;
            for (int k = 0; k < n; k++)
            {
                for (int j = 0; j < nx; j++)
                {
                    for (int i = 0; i < k; i++)
                    {
                        x[k][j] -= x[i][j] * l[k][i];
                    }
                    x[k][j] /= l[k][k];
                }
            }

            // Solve L'*X = Y;
            for (int k = n - 1; k >= 0; k--)
            {
                for (int j = 0; j < nx; j++)
                {
                    for (int i = k + 1; i < n; i++)
                    {
                        x[k][j] -= x[i][j] * l[i][k];
                    }
                    x[k][j] /= l[k][k];
                }
            }

            return new Matrix(x);
        }
开发者ID:kedrzu,项目名称:encog-dotnet-core,代码行数:50,代码来源:CholeskyDecomposition.cs


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