eigvalsh Interface
-
- experimental
- 46 statements
- Source File
public interface eigvalsh
Returns the eigenvalues , , for a real symmetric or complex Hermitian square matrix. (Specification)
Summary
Function interface for computing the eigenvalues of a real symmetric or complex hermitian square matrix.
Description
This interface provides functions for returning the eigenvalues of a real symmetric or complex Hermitian
square matrix. Supported data types include real and complex. The matrix must be symmetric
(if real) or Hermitian (if complex). Only the lower or upper half of the matrix is accessed,
and the user can select which using the optional upper_a flag (default: use lower half).
An error stop is thrown in case of failure; otherwise, error information can be returned
as an optional type(linalg_state_type) output flag.
Functions
private module function stdlib_linalg_eigvalsh_c(a, upper_a, err) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=sp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
|
| type(linalg_state_type), | intent(out) | :: | err |
[optional] state return flag. On error if not requested, the code will stop |
Return Value real(kind=sp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_d(a, upper_a, err) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=dp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
|
| type(linalg_state_type), | intent(out) | :: | err |
[optional] state return flag. On error if not requested, the code will stop |
Return Value real(kind=dp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_noerr_c(a, upper_a) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=sp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
Return Value real(kind=sp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_noerr_d(a, upper_a) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=dp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
Return Value real(kind=dp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_noerr_s(a, upper_a) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=sp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
Return Value real(kind=sp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_noerr_z(a, upper_a) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=dp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
Return Value real(kind=dp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_s(a, upper_a, err) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=sp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
|
| type(linalg_state_type), | intent(out) | :: | err |
[optional] state return flag. On error if not requested, the code will stop |
Return Value real(kind=sp), allocatable, (:)
Array of singular values
private module function stdlib_linalg_eigvalsh_z(a, upper_a, err) result(lambda)
Return an array of eigenvalues of real symmetric / complex hermitian A
Arguments
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| complex(kind=dp), | intent(in), | target | :: | a(:,:) |
Input matrix A[m,n] |
|
| logical(kind=lk), | intent(in), | optional | :: | upper_a |
[optional] Should the upper/lower half of A be used? Default: lower |
|
| type(linalg_state_type), | intent(out) | :: | err |
[optional] state return flag. On error if not requested, the code will stop |
Return Value real(kind=dp), allocatable, (:)
Array of singular values