Managed Linear Algebra Operations.Band Multiply And Add In Place Method
Definition
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 8.1.23
Overload List
Band | Performs one of the matrix-vector operations y := alpha*A*x + beta*y, or y := alpha*AT*x + beta*y, or y := alpha*AH*x + beta*y, where alpha and beta are scalars, x and y are vectors and A is an m by n band matrix, with kl sub-diagonals and ku super-diagonals. |
Band | Sum of the product of a general band matrix and vector and a scaled vector. |
BandMultiplyAndAddInPlace(TransposeOperation, Int32, Int32, Int32, Int32, Complex<Double>, Array2D<Complex<Double>>, ArraySlice<Complex<Double>>, Complex<Double>, ArraySlice<Complex<Double>>)
Performs one of the matrix-vector operations y := alpha*A*x + beta*y, or y := alpha*AT*x + beta*y, or y := alpha*AH*x + beta*y, where alpha and beta are scalars, x and y are vectors and A is an m by n band matrix, with kl sub-diagonals and ku super-diagonals.
public override void BandMultiplyAndAddInPlace(
TransposeOperation trans,
int m,
int n,
int kl,
int ku,
Complex<double> alpha,
Array2D<Complex<double>> a,
ArraySlice<Complex<double>> x,
Complex<double> beta,
ArraySlice<Complex<double>> y
)
Parameters
- trans TransposeOperation
On entry, TRANS specifies the operation to be performed as follows: TRANS = 'N' or 'n' y := alpha*A*x + beta*y. TRANS = 'T' or 't' y := alpha*AT*x + beta*y. TRANS = 'C' or 'c' y := alpha*AH*x + beta*y.
- m Int32
On entry, M specifies the number of rows of the matrix A. M must be at least zero.
- n Int32
On entry, N specifies the number of columns of the matrix A. N must be at least zero.
- kl Int32
On entry, KL specifies the number of sub-diagonals of the matrix A. KL must satisfy 0 .le. KL.
- ku Int32
On entry, KU specifies the number of super-diagonals of the matrix A. KU must satisfy 0 .le. KU.
- alpha Complex<Double>
On entry, ALPHA specifies the scalar alpha.
- a Array2D<Complex<Double>>
A is COMPLEX*16 array of DIMENSION ( LDA, n ). Before entry, the leading ( kl + ku + 1 ) by n part of the array A must contain the matrix of coefficients, supplied column by column, with the leading diagonal of the matrix in row ( ku + 1 ) of the array, the first super-diagonal starting at position 2 in row ku, the first sub-diagonal starting at position 1 in row ( ku + 2 ), and so on. Elements in the array A that do not correspond to elements in the band matrix (such as the top left ku by ku triangle) are not referenced. The following program segment will transfer a band matrix from conventional full matrix storage to band storage: DO 20, J = 1, N K = KU + 1 - J DO 10, I = MAX( 1, J - KU ), MIN( M, J + KL ) A( K + I, J ) = matrix( I, J ) 10 CONTINUE 20 CONTINUE
On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least ( kl + ku + 1 ).
- x ArraySlice<Complex<Double>>
X is COMPLEX*16 array of DIMENSION at least ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( m - 1 )*abs( INCX ) ) otherwise. Before entry, the incremented array X must contain the vector x.
On entry, INCX specifies the increment for the elements of X. INCX must not be zero.
- beta Complex<Double>
On entry, BETA specifies the scalar beta. When BETA is supplied as zero then Y need not be set on input.
- y ArraySlice<Complex<Double>>
Y is COMPLEX*16 array of DIMENSION at least ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at least ( 1 + ( n - 1 )*abs( INCY ) ) otherwise. Before entry, the incremented array Y must contain the vector y. On exit, Y is overwritten by the updated vector y.
On entry, INCY specifies the increment for the elements of Y. INCY must not be zero.
Implements
ILinearAlgebraOperations<T>.BandMultiplyAndAddInPlace(TransposeOperation, Int32, Int32, Int32, Int32, T, Array2D<T>, ArraySlice<T>, T, ArraySlice<T>)Remarks
Further Details:
Level 2 Blas routine. The vector and matrix arguments are not referenced when N = 0, or M = 0 -- 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.
Authors: Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver, NAG Ltd.
Date: November 2011
BandMultiplyAndAddInPlace(TransposeOperation, Int32, Int32, Int32, Int32, Double, Array2D<Double>, ArraySlice<Double>, Double, ArraySlice<Double>)
public override void BandMultiplyAndAddInPlace(
TransposeOperation transA,
int m,
int n,
int kl,
int ku,
double alpha,
Array2D<double> a,
ArraySlice<double> x,
double beta,
ArraySlice<double> y
)
Parameters
- transA TransposeOperation
- Specifies the operation to be performed on the matrix a.
- m Int32
- The number of rows in the matrix a.
- n Int32
- The number of columns in the matrix a.
- kl Int32
- The lower bandwidth of the matrix a.
- ku Int32
- The upper bandwidth of the matrix a.
- alpha Double
- The scalar used to multiply the matrix-vector product.
- a Array2D<Double>
- Reference to the first element in a one-dimensional array that contains the elements of the matrix.
- x ArraySlice<Double>
- A reference to a one-dimensional array containing the elements of the vector x.
- beta Double
- The scalar used to multiply y.
- y ArraySlice<Double>
- A reference to a one-dimensional array containing the elements of the vector y. The elements of y are overwritten with the result.