stevd Interface

public interface stevd

STEVD computes all eigenvalues and, optionally, eigenvectors of a real symmetric tridiagonal matrix. 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 pure subroutine dstevd(jobz, n, d, e, z, ldz, work, lwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(inout) :: d(*)
real(kind=dp), intent(inout) :: e(*)
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 pure subroutine sstevd(jobz, n, d, e, z, ldz, work, lwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(inout) :: d(*)
real(kind=sp), intent(inout) :: e(*)
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_dstevd()

Arguments

None

public interface stdlib_sstevd()

Arguments

None