zlangt.f man page

zlangt.f —

Synopsis

Functions/Subroutines

DOUBLE PRECISION function zlangt (NORM, N, DL, D, DU)
ZLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix.

Function/Subroutine Documentation

DOUBLE PRECISION function zlangt (characterNORM, integerN, complex*16, dimension( * )DL, complex*16, dimension( * )D, complex*16, dimension( * )DU)

ZLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix.

Purpose:

ZLANGT  returns the value of the one norm,  or the Frobenius norm, or
the  infinity norm,  or the  element of  largest absolute value  of a
complex tridiagonal matrix A.

Returns:

ZLANGT

   ZLANGT = ( 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 ZLANGT as described
above.

N

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

DL

DL is COMPLEX*16 array, dimension (N-1)
The (n-1) sub-diagonal elements of A.

D

D is COMPLEX*16 array, dimension (N)
The diagonal elements of A.

DU

DU is COMPLEX*16 array, dimension (N-1)
The (n-1) 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 107 of file zlangt.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

zlangt(3) is an alias of zlangt.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK