Triangular banded | F_STBMV/F_DTBMV/F_CTBMV/F_ZTBMV | |
Name | F_STBMV/F_DTBMV/F_CTBMV/F_ZTBMV | |
| Triangular banded | |
Purpose | F_xTBMV multiplies a vector x by a banded triangular matrix (T), its transpose | |
| (TT), or its conjugate transpose (T*), and copies the resulting vector to the | |
| vector operand x. If n is less than or equal to zero, this routine returns | |
| immediately. |
|
|
| x ← αTx |
|
| x ← αTT x |
|
| x ← αT∗x |
| Refer to “STBMV/DTBMV/CTBMV/ZTBMV” on page 294 for a description of | |
| the equivalent HP MLIB legacy BLAS subprograms. | |
Matrix | Triangular band matrices are stored in a compressed form that takes | |
Storage | advantage of knowing the positions of the only elements that can be nonzero. | |
| Refer to the examples in “STBMV/DTBMV/CTBMV/ZTBMV” on page 294 for | |
| information about the storage of triangular band matrices. | |
Usage | VECLIB |
|
| INTEGER*4 | DIAG, INCX, K, LDA, N, TRANS, UPLO |
| REAL*4 | ALPHA |
| REAL*4 | A( LDA, * ), X( * ) |
| SUBROUTINE F_STBMV (UPLO, TRANS, DIAG, N, K, ALPHA, A, LDA, X, | |
| INCX) |
|
| INTEGER*4 | DIAG, INCX, K, LDA, N, TRANS, UPLO |
| REAL*8 | ALPHA |
| REAL*8 | A( LDA, * ), X( * ) |
| SUBROUTINE F_DTBMV (UPLO, TRANS, DIAG, N, K, ALPHA, A, LDA, | |
| X, INCX) |
|
| INTEGER*4 | DIAG, INCX, K, LDA, N, TRANS, UPLO |
| COMPLEX*8 | ALPHA |
| COMPLEX*8 | A( LDA, * ), X( * ) |
| SUBROUTINE F_CTBMV (UPLO, TRANS, DIAG, N, K, ALPHA, A, LDA, | |
| X, INCX) |
|
Chapter 3 Basic Matrix Operations 397