syevd Interface

public interface syevd

SYEVD computes all eigenvalues and, optionally, eigenvectors of a real symmetric matrix A. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none. Because of large use of BLAS of level 3, SYEVD needs N**2 more workspace than DSYEVX.


Subroutines

public subroutine dsyevd(jobz, uplo, n, a, lda, w, work, lwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=dp), intent(out) :: w(*)
real(kind=dp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
integer(kind=ilp), intent(out) :: iwork(*)
integer(kind=ilp), intent(in) :: liwork
integer(kind=ilp), intent(out) :: info

public subroutine ssyevd(jobz, uplo, n, a, lda, w, work, lwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=sp), intent(out) :: w(*)
real(kind=sp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
integer(kind=ilp), intent(out) :: iwork(*)
integer(kind=ilp), intent(in) :: liwork
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_dsyevd()

Arguments

None

public interface stdlib_ssyevd()

Arguments

None