Diagonalization contains a procedure for finding the eigenvalues and eigenvectors of a real symmetric matrix stored in upper triangular form. The procedure is, in fact, a front end to the public domain LAPACK subroutine DSPEV which is supplied with the library.
Module | Variables |
---|---|
DEFINITIONS | DP |
STATUS | ERROR |
None.
There is a single public subroutine in this module.
Subroutine | Purpose |
---|---|
SYMMETRIC_UPPER | Find the eigenvalues and eigenvectors of a real symmetric matrix stored in upper triangular form. |
Argument | Type | Intent | Optional | Purpose |
---|---|---|---|---|
MATRIX | Real(:) | InOut | No | The matrix. |
EIGENVALUES | Real(:) | Out | No | The eigenvalues. |
EIGENVECTORS | Real(:,:) | Out | Yes | The eigenvectors. |
Error | Meaning |
---|---|
Array dimension error. | There is an inconsistency between the array dimensions of MATRIX, EIGENVALUES and EIGENVECTORS. |
Diagonalization error. | The matrix cannot be diagonalized for some reason. |
Stable.