Developer Reference

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.