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zlangt.f(3) LAPACK zlangt.f(3)

NAME

zlangt.f -

SYNOPSIS

Functions/Subroutines


DOUBLE PRECISION function zlangt (NORM, N, DL, D, DU)
 
ZLANGT

Function/Subroutine Documentation

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

ZLANGT
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:
November 2011
 
Definition at line 107 of file zlangt.f.

Author

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