slangt.f3

!>
!> SLANGT  returns the value of the one norm,  or the Frobenius norm, or
!> the  infinity norm,  or the  element of  largest absolute value  of a
!> real tridiagonal matrix A.
!> 

SLANGT

!>
!>    SLANGT = ( max(abs(A(i,j))), NORM = 'M' or 'm'
!>             (
!>             ( norm1(A),         NORM = '1', 'O' or 'o'
!>             (
!>             ( normI(A),         NORM = 'I' or 'i'
!>             (
!>             ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
!>
!> where  norm1  denotes the  one norm of a matrix (maximum column sum),
!> normI  denotes the  infinity norm  of a matrix  (maximum row sum) and
!> normF  denotes the  Frobenius norm of a matrix (square root of sum of
!> squares).  Note that  max(abs(A(i,j)))  is not a consistent matrix norm.
!> 

NORM

!>          NORM is CHARACTER*1
!>          Specifies the value to be returned in SLANGT as described
!>          above.
!> 

N

!>          N is INTEGER
!>          The order of the matrix A.  N >= 0.  When N = 0, SLANGT is
!>          set to zero.
!> 

DL

!>          DL is REAL array, dimension (N-1)
!>          The (n-1) sub-diagonal elements of A.
!> 

D

!>          D is REAL array, dimension (N)
!>          The diagonal elements of A.
!> 

DU

!>          DU is REAL array, dimension (N-1)
!>          The (n-1) super-diagonal elements of A.
!> 

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