Contents

# mkl_?skymm

Computes matrix-matrix product of a sparse matrix stored using the skyline storage scheme with one-based indexing (deprecated).

## Syntax

Include Files
• mkl.h
Description
This routine is deprecated. Use Use mkl_sparse_?_mmfrom the
Intel® oneAPI Math Kernel Library
The
mkl_?skymm
routine performs a matrix-matrix operation defined as
`C := alpha*A*B + beta*C`
or
`C := alpha*AT*B + beta*C,`
or
`C := alpha*AH*B + beta*C,`
where:
alpha
and
beta
are scalars,
B
and
C
are dense matrices,
A
is an
m
-by-
k
sparse matrix in the skyline storage format,
A
T
is the transpose of
A
, and
A
H
is the conjugate transpose of
A
.
This routine supports only one-based indexing of the input arrays.
Input Parameters
transa
Specifies the operation.
If
transa
=
'N'
or
'n'
, then
C
:=
alpha
*
A
*
B
+
beta
*
C
,
If
transa
=
'T'
or
't'
, then
C
:=
alpha
*
A
T
*
B
+
beta
*
C
,
If
transa
=
'C'
or
'c'
, then
C
:=
alpha
*
A
H
*
B
+
beta
*
C
.
m
Number of rows of the matrix
A
.
n
Number of columns of the matrix
C
.
k
Number of columns of 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
.
General matrices
(
matdescra
[0]
='G')
is not supported.
val
Array containing the set of elements of the matrix
A
in the skyline profile form.
If
matdescrsa
[2]
=
'L'
, then
val
contains elements from the low triangle of the matrix
A
.
If
matdescrsa
[2]
=
'U'
, then
val
contains elements from the upper triangle of the matrix
A
.
Refer to
values
array description in Skyline Storage Scheme for more details.
pntr
Array of length
(
m
+ 1)
for lower triangle, and
(
k
+ 1)
for upper triangle.
It contains the indices specifying the positions of the first element of the matrix
A
in each row (for the lower triangle) or column (for upper triangle) in the
val
array
such that
val
[
pntr
[
i
] - 1]
is the first element in row or column
i
+ 1
. Refer to
pointers
array description in Skyline Storage Scheme for more details.
b
Array, size
ldb
*
n
.
On entry with
transa
=
'N'
or
'n'
k
-by-
n
part of the array
b
must contain the matrix
B
m
-by-
n
part of the array
b
must contain the matrix
B
.
ldb
b
as declared in the calling (sub)program.
beta
Specifies the scalar
beta
.
c
Array, size
ldc
by
n
.
m
-by-
n
part of the array
c
must contain the matrix
C
k
-by-
n
part of the array
c
must contain the matrix
C
.
ldc
c
as declared in the calling (sub)program.
Output Parameters
c
Overwritten by the matrix
(
alpha
*
A
*
B
+
beta
*
C
)
,
(
alpha
*
A
T
*
B
+
beta
*
C
)
, or
(
alpha
*
A
H
*
B
+
beta
*
C
)
.

#### Product and Performance Information

1

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