## Developer Reference

• 2020.2
• 07/15/2020
• Public Content
Contents

# ?sysvx

Uses the diagonal pivoting factorization to compute the solution to the system of linear equations with a real or complex symmetric coefficient matrix A, and provides error bounds on the solution.

## Syntax

Include Files
• mkl.fi
,
lapack.f90
Description
The routine uses the diagonal pivoting factorization to compute the solution to a real or complex system of linear equations
A*X
=
B
, where
A
is a
n
-by-
n
symmetric matrix, the columns of matrix
B
are individual right-hand sides, and the columns of
X
are the corresponding solutions.
Error bounds on the solution and a condition estimate are also provided.
The routine
?sysvx
performs the following steps:
1. If
fact
=
'N'
, the diagonal pivoting method is used to factor the matrix
A
. The form of the factorization is
A
=
U*D*U
T
or
A
=
L*D*L
T
, where
U
(or
L
) is a product of permutation and unit upper (lower) triangular matrices, and
D
is symmetric and block diagonal with 1-by-1 and 2-by-2 diagonal blocks.