gbequ Interface

public interface gbequ

GBEQU computes row and column scalings intended to equilibrate an M-by-N band matrix A and reduce its condition number. R returns the row scale factors and C the column scale factors, chosen to try to make the largest element in each row and column of the matrix B with elements B(i,j)=R(i)A(i,j)C(j) have absolute value 1. R(i) and C(j) are restricted to be between SMLNUM = smallest safe number and BIGNUM = largest safe number. Use of these scaling factors is not guaranteed to reduce the condition number of A but works well in practice.


Subroutines

public pure subroutine cgbequ(m, n, kl, ku, ab, ldab, r, c, rowcnd, colcnd, amax, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: kl
integer(kind=ilp), intent(in) :: ku
complex(kind=sp), intent(in) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
real(kind=sp), intent(out) :: r(*)
real(kind=sp), intent(out) :: c(*)
real(kind=sp), intent(out) :: rowcnd
real(kind=sp), intent(out) :: colcnd
real(kind=sp), intent(out) :: amax
integer(kind=ilp), intent(out) :: info

public pure subroutine dgbequ(m, n, kl, ku, ab, ldab, r, c, rowcnd, colcnd, amax, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: kl
integer(kind=ilp), intent(in) :: ku
real(kind=dp), intent(in) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
real(kind=dp), intent(out) :: r(*)
real(kind=dp), intent(out) :: c(*)
real(kind=dp), intent(out) :: rowcnd
real(kind=dp), intent(out) :: colcnd
real(kind=dp), intent(out) :: amax
integer(kind=ilp), intent(out) :: info

public pure subroutine sgbequ(m, n, kl, ku, ab, ldab, r, c, rowcnd, colcnd, amax, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: kl
integer(kind=ilp), intent(in) :: ku
real(kind=sp), intent(in) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
real(kind=sp), intent(out) :: r(*)
real(kind=sp), intent(out) :: c(*)
real(kind=sp), intent(out) :: rowcnd
real(kind=sp), intent(out) :: colcnd
real(kind=sp), intent(out) :: amax
integer(kind=ilp), intent(out) :: info

public pure subroutine zgbequ(m, n, kl, ku, ab, ldab, r, c, rowcnd, colcnd, amax, info)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: kl
integer(kind=ilp), intent(in) :: ku
complex(kind=dp), intent(in) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
real(kind=dp), intent(out) :: r(*)
real(kind=dp), intent(out) :: c(*)
real(kind=dp), intent(out) :: rowcnd
real(kind=dp), intent(out) :: colcnd
real(kind=dp), intent(out) :: amax
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_cgbequ()

Arguments

None

public interface stdlib_dgbequ()

Arguments

None

public interface stdlib_sgbequ()

Arguments

None

public interface stdlib_zgbequ()

Arguments

None