Developer Reference for Intel® oneAPI Math Kernel Library - C

Developer Reference

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

cblas_?tpmv

Computes a matrix-vector product using a triangular packed matrix.

Syntax

void
cblas_stpmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
float
*ap
,
float
*x
,
const
MKL_INT
incx
);
void
cblas_dtpmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
double
*ap
,
double
*x
,
const
MKL_INT
incx
);
void
cblas_ctpmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
void
*ap
,
void
*x
,
const
MKL_INT
incx
);
void
cblas_ztpmv
(
const
CBLAS_LAYOUT
Layout
,
const
CBLAS_UPLO
uplo
,
const
CBLAS_TRANSPOSE
trans
,
const
CBLAS_DIAG
diag
,
const
MKL_INT
n
,
const
void
*ap
,
void
*x
,
const
MKL_INT
incx
);
Include Files
  • mkl.h
Description
The
?tpmv
 routines perform one of the matrix-vector operations defined as
x
 :=
A
*
x
, or
x
 :=
A
'*
x
, or
x
 := conjg(
A
')*
x
,
where:
x
 is an
n
-element vector,
A
 is an
n
-by-
n
 unit, or non-unit, upper or lower triangular matrix, supplied in packed form.
Input Parameters
Layout
Specifies whether two-dimensional array storage is row-major (
CblasRowMajor
) or column-major (
CblasColMajor
).
uplo
Specifies whether the matrix
A
 is upper or lower triangular:
uplo
 =
CblasUpper
if
uplo
 =
CblasLower
, then the matrix is low triangular.
trans
Specifies the operation:
if
trans
=
CblasNoTrans
, then
x
 :=
A
*
x
;
if
trans
=
CblasTrans
, then
x
 :=
A
'*
x
;
if
trans
=
CblasConjTrans
, then
x
 := conjg(
A
')*
x
.
diag
Specifies whether the matrix
A
 is unit triangular:
if
diag
 =
CblasUnit
 then the matrix is unit triangular;
if
diag
 =
CblasNonUnit
, then the matrix is not unit triangular.
n
Specifies the order of the matrix
A
. The value of
n
 must be at least zero.
ap
Array, size at least
((
n
*(
n
 + 1))/2)
.
For
Layout
 =
CblasColMajor
:
Before entry with
uplo
 =
CblasUpper
, the array
ap
 must contain the upper triangular matrix packed sequentially, column-by-column, so that respectively, and so on. Before entry with
uplo
 =
CblasLower
ap
[0]
 contains
A
1, 1
,
ap
[1]
 and
ap
[2]
 contain
A
1, 2
 and
A
2, 2
, the array
ap
 must contain the lower triangular matrix packed sequentially, column-by-column, so that
ap
[0]
 contains
A
1, 1
,
ap
[1]
 and
ap
[2]
 contain
A
2, 1
 and
A
3, 1
 respectively, and so on. When
diag
 =
CblasUnit
, the diagonal elements of
a
 are not referenced, but are assumed to be unity.
For
Layout
 =
CblasRowMajor
:
Before entry with
uplo
 =
CblasUpper
, the array
ap
 must contain the upper triangular matrix packed sequentially, row-by-row,
ap
[0]
 contains
A
1, 1
,
ap
[1]
 and
ap
[2]
 contain
A
1, 2
 and
A
1, 3
 respectively, and so on.
Before entry with
uplo
 =
CblasLower
, the array
ap
 must contain the lower triangular matrix packed sequentially, row-by-row, so that
ap
[0]
 contains
A
1, 1
,
ap
[1]
 and
ap
[2]
 contain
A
2, 1
 and
A
2, 2
 respectively, and so on.
x
Array, size at least
(1 + (
n
 - 1)*abs(
incx
))
. Before entry, the incremented array
x
 must contain the
n
-element vector
x
.
incx
Specifies the increment for the elements of
x
.
The value of
incx
 must not be zero.
Output Parameters
x
Overwritten with the transformed vector
x
.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.