spgst Interface

public interface spgst

SPGST reduces a real symmetric-definite generalized eigenproblem to standard form, using packed storage. If ITYPE = 1, the problem is Ax = lambdaBx, and A is overwritten by inv(UT)Ainv(U) or inv(L)Ainv(LT) If ITYPE = 2 or 3, the problem is ABx = lambdax or BAx = lambdax, and A is overwritten by UAUT or LTAL. B must have been previously factorized as UTU or LL*T by DPPTRF.


Subroutines

public pure subroutine dspgst(itype, uplo, n, ap, bp, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: itype
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(inout) :: ap(*)
real(kind=dp), intent(in) :: bp(*)
integer(kind=ilp), intent(out) :: info

public pure subroutine sspgst(itype, uplo, n, ap, bp, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: itype
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(inout) :: ap(*)
real(kind=sp), intent(in) :: bp(*)
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_dspgst()

Arguments

None

public interface stdlib_sspgst()

Arguments

None