Solves the symmetric indefinite linear system Ax = b.

Syntax

x = LSolveSI(A,b)

Arguments

Name

Description

A

A symmetric indefinite matrix of real values. The upper triangle of the matrix can be omitted.

b

The right-hand side column vector or a matrix.  If it is a matrix, each column produces a separate vector solution to the system.  The number of rows must be equal to the row/column size of the square matrix A.

Output

Name

Description

x

The solution(s) to the system(s).  It will have the same dimensions as the right-hand side argument b.  For each column in b, there will be a solution in the corresponding column in x.

Example

Solve the symmetric positive indefinite linear system Ax=b.

Syntax

A = [40,2,3;2,40,4;3,4,40]; // symmetric indefinite matrix

b = [1,2;11,22;21,42] // the right hand matrix

x = LSolveSI(A,b)

Result

A solution to the system.

[Matrix] 3 x 2

-0.024106   -0.048213

0.22578     0.45156

0.50423     1.0085

Comments

LSolveSI calls dsysv from LAPACK.

See Also:

LSolveB

LSolveT

LSolveSPD

LSolveSPDB