Extracts the eigenvalues and eigenvectors of a symmetric tri-diagonal matrix.

Syntax

e, v = EigST(diag, offdiag)

Arguments

Name

Description

diag

A vector of the main diagonal elements of the symmetric tridiagonal matrix A.

offdiag

A vector of the lower or upper off diagonal elements.

Output

Name

Description

e

A vector of the eigenvalues of the matrix.

v

A matrix whose columns are the eigenvectors of A.

Example

Extract the eigenvalues of the symmetric tri-diagonal matrix [40,2,0;2,40,4;0,4,40].

Syntax

diag = [40,40,40];

offdiag = [2,4];

e = EigST(diag,offdiag);

Result

A row vector of the eigenvalues.

e =  35.528  40  44.472

Comments

EigST calls dstev from LAPACK.

See Also:

EigS

EigSB

LSolveT