spevd Interface

public interface spevd

SPEVD computes all the eigenvalues and, optionally, eigenvectors of a real symmetric matrix A in packed storage. 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.


Subroutines

public subroutine dspevd(jobz, uplo, n, ap, w, z, ldz, 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) :: ap(*)
real(kind=dp), intent(out) :: w(*)
real(kind=dp), intent(out) :: z(ldz,*)
integer(kind=ilp), intent(in) :: ldz
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 sspevd(jobz, uplo, n, ap, w, z, ldz, 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) :: ap(*)
real(kind=sp), intent(out) :: w(*)
real(kind=sp), intent(out) :: z(ldz,*)
integer(kind=ilp), intent(in) :: ldz
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_dspevd()

Arguments

None

public interface stdlib_sspevd()

Arguments

None