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#region Translated by Jose Antonio De Santiago-Castillo.
//Translated by Jose Antonio De Santiago-Castillo.
//E-mail:JAntonioDeSantiago@gmail.com
//Website: www.DotNumerics.com
//
//Fortran to C# Translation.
//Translated by:
//F2CSharp Version 0.72 (Dicember 7, 2009)
//Code Optimizations: , assignment operator, for-loop: array indexes
//
#endregion
using System;
using DotNumerics.FortranLibrary;
namespace DotNumerics.LinearAlgebra.CSLapack
{
/// <summary>
/// Purpose
/// =======
///
/// DGER performs the rank 1 operation
///
/// A := alpha*x*y' + A,
///
/// where alpha is a scalar, x is an m element vector, y is an n element
/// vector and A is an m by n matrix.
///
///</summary>
public class DGER
{
#region Dependencies
XERBLA _xerbla;
#endregion
#region Variables
const double ZERO = 0.0E+0;
#endregion
public DGER(XERBLA xerbla)
{
#region Set Dependencies
this._xerbla = xerbla;
#endregion
}
public DGER()
{
#region Dependencies (Initialization)
XERBLA xerbla = new XERBLA();
#endregion
#region Set Dependencies
this._xerbla = xerbla;
#endregion
}
/// <summary>
/// Purpose
/// =======
///
/// DGER performs the rank 1 operation
///
/// A := alpha*x*y' + A,
///
/// where alpha is a scalar, x is an m element vector, y is an n element
/// vector and A is an m by n matrix.
///
///</summary>
/// <param name="M">
/// - INTEGER.
/// On entry, M specifies the number of rows of the matrix A.
/// M must be at least zero.
/// Unchanged on exit.
///</param>
/// <param name="N">
/// - INTEGER.
/// On entry, N specifies the number of columns of the matrix A.
/// N must be at least zero.
/// Unchanged on exit.
///</param>
/// <param name="ALPHA">
/// - DOUBLE PRECISION.
/// On entry, ALPHA specifies the scalar alpha.
/// Unchanged on exit.
///</param>
/// <param name="X">
/// - DOUBLE PRECISION array of dimension at least
/// ( 1 + ( m - 1 )*abs( INCX ) ).
/// Before entry, the incremented array X must contain the m
/// element vector x.
/// Unchanged on exit.
///</param>
/// <param name="INCX">
/// - INTEGER.
/// On entry, INCX specifies the increment for the elements of
/// X. INCX must not be zero.
/// Unchanged on exit.
///</param>
/// <param name="Y">
/// - DOUBLE PRECISION array of dimension at least
/// ( 1 + ( n - 1 )*abs( INCY ) ).
/// Before entry, the incremented array Y must contain the n
/// element vector y.
/// Unchanged on exit.
///</param>
/// <param name="INCY">
/// - INTEGER.
/// On entry, INCY specifies the increment for the elements of
/// Y. INCY must not be zero.
/// Unchanged on exit.
///</param>
/// <param name="A">
/// := alpha*x*y' + A,
///</param>
/// <param name="LDA">
/// - INTEGER.
/// On entry, LDA specifies the first dimension of A as declared
/// in the calling (sub) program. LDA must be at least
/// max( 1, m ).
/// Unchanged on exit.
///
///</param>
public void Run(int M, int N, double ALPHA, double[] X, int offset_x, int INCX, double[] Y, int offset_y
, int INCY, ref double[] A, int offset_a, int LDA)
{
#region Variables
double TEMP = 0; int I = 0; int INFO = 0; int IX = 0; int J = 0; int JY = 0; int KX = 0;
#endregion
#region Implicit Variables
int A_J = 0;
#endregion
#region Array Index Correction
int o_x = -1 + offset_x; int o_y = -1 + offset_y; int o_a = -1 - LDA + offset_a;
#endregion
#region Prolog
// * .. Scalar Arguments ..
// * ..
// * .. Array Arguments ..
// * ..
// *
// * Purpose
// * =======
// *
// * DGER performs the rank 1 operation
// *
// * A := alpha*x*y' + A,
// *
// * where alpha is a scalar, x is an m element vector, y is an n element
// * vector and A is an m by n matrix.
// *
// * Arguments
// * ==========
// *
// * M - INTEGER.
// * On entry, M specifies the number of rows of the matrix A.
// * M must be at least zero.
// * Unchanged on exit.
// *
// * N - INTEGER.
// * On entry, N specifies the number of columns of the matrix A.
// * N must be at least zero.
// * Unchanged on exit.
// *
// * ALPHA - DOUBLE PRECISION.
// * On entry, ALPHA specifies the scalar alpha.
// * Unchanged on exit.
// *
// * X - DOUBLE PRECISION array of dimension at least
// * ( 1 + ( m - 1 )*abs( INCX ) ).
// * Before entry, the incremented array X must contain the m
// * element vector x.
// * Unchanged on exit.
// *
// * INCX - INTEGER.
// * On entry, INCX specifies the increment for the elements of
// * X. INCX must not be zero.
// * Unchanged on exit.
// *
// * Y - DOUBLE PRECISION array of dimension at least
// * ( 1 + ( n - 1 )*abs( INCY ) ).
// * Before entry, the incremented array Y must contain the n
// * element vector y.
// * Unchanged on exit.
// *
// * INCY - INTEGER.
// * On entry, INCY specifies the increment for the elements of
// * Y. INCY must not be zero.
// * Unchanged on exit.
// *
// * A - DOUBLE PRECISION array of DIMENSION ( LDA, n ).
// * Before entry, the leading m by n part of the array A must
// * contain the matrix of coefficients. On exit, A is
// * overwritten by the updated matrix.
// *
// * LDA - INTEGER.
// * On entry, LDA specifies the first dimension of A as declared
// * in the calling (sub) program. LDA must be at least
// * max( 1, m ).
// * Unchanged on exit.
// *
// *
// * Level 2 Blas routine.
// *
// * -- Written on 22-October-1986.
// * Jack Dongarra, Argonne National Lab.
// * Jeremy Du Croz, Nag Central Office.
// * Sven Hammarling, Nag Central Office.
// * Richard Hanson, Sandia National Labs.
// *
// *
// * .. Parameters ..
// * ..
// * .. Local Scalars ..
// * ..
// * .. External Subroutines ..
// * ..
// * .. Intrinsic Functions ..
// INTRINSIC MAX;
// * ..
// *
// * Test the input parameters.
// *
#endregion
#region Body
INFO = 0;
if (M < 0)
{
INFO = 1;
}
else
{
if (N < 0)
{
INFO = 2;
}
else
{
if (INCX == 0)
{
INFO = 5;
}
else
{
if (INCY == 0)
{
INFO = 7;
}
else
{
if (LDA < Math.Max(1, M))
{
INFO = 9;
}
}
}
}
}
if (INFO != 0)
{
this._xerbla.Run("DGER ", INFO);
return;
}
// *
// * Quick return if possible.
// *
if ((M == 0) || (N == 0) || (ALPHA == ZERO)) return;
// *
// * Start the operations. In this version the elements of A are
// * accessed sequentially with one pass through A.
// *
if (INCY > 0)
{
JY = 1;
}
else
{
JY = 1 - (N - 1) * INCY;
}
if (INCX == 1)
{
for (J = 1; J <= N; J++)
{
if (Y[JY + o_y] != ZERO)
{
TEMP = ALPHA * Y[JY + o_y];
A_J = J * LDA + o_a;
for (I = 1; I <= M; I++)
{
A[I + A_J] += X[I + o_x] * TEMP;
}
}
JY += INCY;
}
}
else
{
if (INCX > 0)
{
KX = 1;
}
else
{
KX = 1 - (M - 1) * INCX;
}
for (J = 1; J <= N; J++)
{
if (Y[JY + o_y] != ZERO)
{
TEMP = ALPHA * Y[JY + o_y];
IX = KX;
A_J = J * LDA + o_a;
for (I = 1; I <= M; I++)
{
A[I + A_J] += X[IX + o_x] * TEMP;
IX += INCX;
}
}
JY += INCY;
}
}
// *
return;
// *
// * End of DGER .
// *
#endregion
}
}
}