eigen Subroutine

public subroutine eigen(A, eigenvalues, eigenvectors)

eigen

Description

Calculate the eigenvalues and eigenvectors of a real symmetric matrix A using LAPACK’s dsyev. The eigenvectors are stored in the columns of eigenvectors. The eigenvalues are stored in eigenvalues.

Arguments

Type IntentOptional Attributes Name
real(kind=pr), intent(inout) :: A(:,:)
real(kind=pr), intent(out) :: eigenvalues(:)
real(kind=pr), intent(out), optional :: eigenvectors(:,:)

Calls

proc~~eigen~~CallsGraph proc~eigen eigen none~dsyev dsyev proc~eigen->none~dsyev

Called by

proc~~eigen~~CalledByGraph proc~eigen eigen proc~lambda1 lambda1 proc~lambda1->proc~eigen proc~critical_line critical_line proc~critical_line->proc~lambda1 proc~f_critical F_critical proc~critical_line->proc~f_critical proc~df_critical df_critical proc~critical_line->proc~df_critical proc~look_for_cep look_for_cep proc~critical_line->proc~look_for_cep proc~critical_point critical_point proc~critical_point->proc~lambda1 proc~critical_point->proc~f_critical proc~critical_point->proc~df_critical proc~f_cep F_cep proc~f_cep->proc~lambda1 proc~f_critical->proc~lambda1 proc~df_cep df_cep proc~df_cep->proc~f_cep proc~df_critical->proc~f_critical proc~get_critical_constants get_critical_constants proc~get_critical_constants->proc~critical_point proc~look_for_cep->proc~f_cep proc~look_for_cep->proc~df_cep proc~init_pcsaft init_pcsaft proc~init_pcsaft->proc~get_critical_constants

Variables

Type Visibility Attributes Name Initial
real(kind=pr), public :: Ain(size(A,1),size(A,1))
integer, public :: istat
integer, public :: n
real(kind=pr), public :: work(size(A,1)*10)

Interfaces

interface

  • subroutine dsyev(JOBZ, UPLO, N, A, lda, W, WORK, LWORK, INFO)

    Arguments

    Type IntentOptional Attributes Name
    character(len=1) :: JOBZ
    character(len=1) :: UPLO
    integer :: N
    double precision :: A(lda,*)
    integer :: lda
    double precision :: W(*)
    double precision :: WORK(*)
    integer :: LWORK
    integer :: INFO