slanst.f(3) LAPACK slanst.f(3)
NAME
slanst.f -
SYNOPSIS
Functions/Subroutines
REAL function slanst (NORM, N, D, E)
SLANST 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
REAL function slanst (characterNORM, integerN, real, dimension( * )D, real, dimension( * )E)
SLANST 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:
SLANST 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:
SLANST
SLANST = ( 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 SLANST as described
above.
N
N is INTEGER
The order of the matrix A. N >= 0. When N = 0, SLANST is
set to zero.
D
D is REAL array, dimension (N)
The diagonal elements of A.
E
E is REAL 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.
Date:
September 2012
Definition at line 101 of file slanst.f.
Author
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Version 3.4.2 Tue Sep 25 2012 slanst.f(3)