Contents

# mkl_?skysv

Solves a system of linear equations for a sparse matrix in the skyline format with one-based indexing (deprecated).

## Syntax

Include Files
• mkl.h
Description
This routine is deprecated. Use mkl_sparse_?_trsvfrom the
Intel® oneAPI Math Kernel Library
The
mkl_?skysv
routine solves a system of linear equations with matrix-vector operations for a sparse matrix in the skyline storage format:
`y := alpha*inv(A)*x`
or
`y := alpha*inv(AT)*x,`
where:
alpha
is scalar,
x
and
y
are vectors,
A
is a sparse upper or lower triangular matrix with unit or non-unit main diagonal,
A
T
is the transpose of
A
.
This routine supports only one-based indexing of the input arrays.
Input Parameters
transa
Specifies the system of linear equations.
If
transa
=
'N'
or
'n'
, then
y
:=
alpha
*inv(
A
)*
x
If
transa
=
'T'
or
't'
or
'C'
or
'c'
, then
y
:=
alpha
*inv(
A
T
)*
x
,
m
Number of rows 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
matdescra
[2]
=
'L'
, then
val
contains elements from the low triangle of the matrix
A
.
If
matdescsa
[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 in the
val
the positions of the first element in each row (column) of the matrix
A
. Refer to
pointers
array description in Skyline Storage Scheme for more details.
x
Array, size at least
m
.
On entry, the array
x
must contain the vector
x
. The elements are accessed with unit increment.
y
Array, size at least
m
.
On entry, the array
y
must contain the vector
y
. The elements are accessed with unit increment.
Output Parameters
y
Contains solution vector
x
.

#### Product and Performance Information

1

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