?tpmv
Compute the product of a vector and a packed, triangular expanded matrix.
That is, 
. x is a vector including n elements, and A is an n*n unit/non-unit, triangular expanded matrix.
Interface Definition
C interface:
void cblas_stpmv(const enum CBLAS_ORDER order, const enum CBLAS_UPLO Uplo, const enum CBLAS_TRANSPOSE TransA, const enum CBLAS_DIAG Diag, const BLASINT N, const float *Ap, float *X, const BLASINT incX);
void cblas_dtpmv(const enum CBLAS_ORDER order, const enum CBLAS_UPLO Uplo, const enum CBLAS_TRANSPOSE TransA, const enum CBLAS_DIAG Diag, const BLASINT N, const double *Ap, double *X, const BLASINT incX);
void cblas_ctpmv(const enum CBLAS_ORDER order, const enum CBLAS_UPLO Uplo, const enum CBLAS_TRANSPOSE TransA, const enum CBLAS_DIAG Diag, const BLASINT N, const void *Ap, void *X, const BLASINT incX);
void cblas_ztpmv(const enum CBLAS_ORDER order, const enum CBLAS_UPLO Uplo, const enum CBLAS_TRANSPOSE TransA, const enum CBLAS_DIAG Diag, const BLASINT N, const void *Ap, void *X, const BLASINT incX);
Fortran interface:
CALL STPMV(UPLO, TRANS, DIAG, N, AP, X, INCX)
CALL DTPMV(UPLO, TRANS, DIAG, N, AP, X, INCX)
CALL CTPMV(UPLO, TRANS, DIAG, N, AP, X, INCX)
CALL ZTPMV(UPLO, TRANS, DIAG, N, AP, X, INCX)
Parameters
Parameter |
Type |
Description |
Input/Output |
|---|---|---|---|
order |
Enumeration type CBLAS_ORDER |
Whether the matrix is in row- or column-major order. |
Input |
Uplo |
Enumeration type CBLAS_UPLO |
Whether to use the upper triangle or lower triangle of matrix A.
|
Input |
TransA |
Enumeration type CBLAS_TRANSPOSE |
Whether matrix A is non-transposed, transposed, or conjugated.
|
Input |
Diag |
|
Whether A is a unit triangular matrix.
|
Input |
N |
Integer |
Order of the matrix A. N must be greater than or equal to 0. |
Input |
Ap |
|
The size of a packed triangular matrix is at least (N*(N+1)/2). |
Input |
X |
|
Vector X. The vector scale is at least (1+(N-1)*abs(incX)). |
Input/Output |
incX |
Integer |
Increment for elements in X. The value cannot be 0. |
Input |
Dependency
#include "kblas.h"
Examples
C interface:
int n = 4, incx = 1;
float x[4] = {4.0, 3.0, 2.0, 1.0};
/**
* | 1.0 1.0 1.0 3.0 |
* A = | . 3.0 3.0 2.0 |
* | . . 2.0 3.0 |
* | . . . 1.0 |
*/
float ap[10] = {1.0, 1.0, 3.0, 1.0, 3.0, 2.0, 3.0, 2.0, 3.0, 1.0};
cblas_stpmv(CblasColMajor, CblasUpper, CblasTrans, CblasNonUnit, n, ap, x, incx);
/**
* Output x = |4.0, 13.0, 17.0, 25.0|
*/
Fortran interface:
INTEGER :: N=4, INCX=1
REAL(4) :: X(4), AP(10)
DATA X/4.0, 3.0, 2.0, 1.0/
DATA AP/1.0, 1.0, 3.0, 1.0, 3.0, 2.0, 3.0, 2.0, 3.0, 1.0/
EXTERNAL STPMV
CALL STPMV('U', 'T', 'N', N, AP, X, INCX)
* Output X = |4.0, 13.0, 17.0, 25.0|