SRC/dlanst.f(3)            Library Functions Manual            SRC/dlanst.f(3)

NAME
       SRC/dlanst.f

SYNOPSIS
   Functions/Subroutines
       double precision function dlanst (norm, n, d, e)
           DLANST returns the value of the 1-norm, or the Frobenius norm, or
           the infinity norm, or the element of largest absolute value of a
           real symmetric tridiagonal matrix.

Function/Subroutine Documentation
   double precision function dlanst (character norm, integer n, double
       precision, dimension( * ) d, double precision, dimension( * ) e)
       DLANST returns the value of the 1-norm, or the Frobenius norm, or the
       infinity norm, or the element of largest absolute value of a real
       symmetric tridiagonal matrix.

       Purpose:


            DLANST  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 symmetric tridiagonal matrix A.

       Returns
           DLANST

               DLANST = ( 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.

       Parameters
           NORM

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

           N

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

           D

                     D is DOUBLE PRECISION array, dimension (N)
                     The diagonal elements of A.

           E

                     E is DOUBLE PRECISION array, dimension (N-1)
                     The (n-1) sub-diagonal or super-diagonal elements of A.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 99 of file dlanst.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/dlanst.f(3)