Contents

# mkl_?bsrmv

Computes matrix - vector product of a sparse matrix stored in the BSR format (deprecated).

## Syntax

Include Files
• mkl.h
Description
This routine is deprecated. Use mkl_sparse_?_mvfrom the
Intel® oneAPI Math Kernel Library
The
mkl_?bsrmv
routine performs a matrix-vector operation defined as
`y := alpha*A*x + beta*y`
or
`y := alpha*AT*x + beta*y,`
where:
alpha
and
beta
are scalars,
x
and
y
are vectors,
A
is an
m
-by-
k
block sparse matrix in the BSR format,
A
T
is the transpose of
A
.
This routine supports a BSR format both with one-based indexing and zero-based indexing.
Input Parameters
transa
Specifies the operation.
If
transa
=
'N'
or
'n'
, then the matrix-vector product is computed as
y
:=
alpha
*
A
*
x
+
beta
*
y
If
transa
=
'T'
or
't'
or
'C'
or
'c'
, then the matrix-vector product is computed as
y
:=
alpha
*
A
T
*
x
+
beta
*
y
,
m
Number of block rows of the matrix
A
.
k
Number of block columns of the matrix
A
.
lb
Size of the block in the matrix
A
.
alpha
Specifies the scalar
alpha
.
matdescra
Array of six elements, specifies properties of the matrix used for operation. Only first four array elements are used, their possible values are given in
Table “Possible Values of the Parameter
matdescra
(
descra
)”
. Possible combinations of element values of this parameter are given in
Table “Possible Combinations of Element Values of the Parameter
matdescra
.
val
Array containing elements of non-zero blocks of the matrix
A
. Its length is equal to the number of non-zero blocks in the matrix
A
multiplied by
lb
*
lb
.
Refer to
values
array description in BSR Format for more details.
indx
For one-based indexing, array containing the column indices plus one for each non-zero block of the matrix
A
. For zero-based indexing, array containing the column indices for each non-zero block of the matrix
A
.
Its length is equal to the number of non-zero blocks in the matrix
A
.
Refer to
columns
array description in BSR Format for more details.
pntrb
Array of length
m
.
This array contains row indices, such that
pntrb
[
i
] -
pntrb

is the first index of block row
i
in the array
indx
Refer to
pointerB
array description in BSR Format for more details.
pntre
Array of length
m
.
For zero-based indexing this array contains row indices, such that
pntre
[
i
] -
pntrb
 - 1
is the last index of block row
i
in the array
indx
.
Refer to
pointerE
array description in BSR Format for more details.
x
Array, size at least
(
k
*
lb
)
if
transa
=
'N'
or
'n'
, and at least
(
m
*
lb
)
otherwise. On entry, the array
x
must contain the vector
x
.
beta
Specifies the scalar
beta
.
y
Array, size at least
(
m
*
lb
)
if
transa
=
'N'
or
'n'
, and at least
(
k
*
lb
)
otherwise. On entry, the array
y
must contain the vector
y
.
Output Parameters
y
Overwritten by the updated vector
y
.

#### Product and Performance Information

1

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