eigvals Interface

public interface eigvals

Returns the eigenvalues , , for square matrix . (Specification)

Summary

Function interface for computing the eigenvalues of a square matrix.

Description

This interface provides functions for returning the eigenvalues of a general square matrix. Supported data types include real and complex, and no assumption is made on the matrix structure. An error stop is thrown in case of failure; otherwise, error information can be returned as an optional type(linalg_state_type) output flag.

Note

The solution is based on LAPACK's general eigenproblem solvers *GEEV.

Note

BLAS/LAPACK backends do not currently support extended precision (xdp).


Functions

private module function stdlib_linalg_eigvals_generalized_c(a, b, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

complex(kind=sp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_generalized_d(a, b, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

real(kind=dp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_generalized_s(a, b, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

real(kind=sp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_generalized_z(a, b, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

complex(kind=dp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_generalized_c(a, b) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

complex(kind=sp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_generalized_d(a, b) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

real(kind=dp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_generalized_s(a, b) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

real(kind=sp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_generalized_z(a, b) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

complex(kind=dp), intent(inout), dimension(:,:), target :: b

Generalized problem matrix B[n,n]

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_standard_c(a) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_standard_d(a) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_standard_s(a) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_noerr_standard_z(a) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_standard_c(a, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_standard_d(a, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=dp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_standard_s(a, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
real(kind=sp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=sp), allocatable, (:)

Array of singular values

private module function stdlib_linalg_eigvals_standard_z(a, err) result(lambda)

Return an array of eigenvalues of matrix A.

Arguments

Type IntentOptional Attributes Name
complex(kind=dp), intent(in), dimension(:,:), target :: a

Input matrix A[m,n]

type(linalg_state_type), intent(out) :: err

[optional] state return flag. On error if not requested, the code will stop

Return Value complex(kind=dp), allocatable, (:)

Array of singular values