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.TH ZLANGT l "15 June 2000" "LAPACK version 3.0" ")"
.SH NAME
ZLANGT - return 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
.SH SYNOPSIS
.TP 17
DOUBLE PRECISION
FUNCTION ZLANGT( NORM, N, DL, D, DU )
.TP 17
.ti +4
CHARACTER
NORM
.TP 17
.ti +4
INTEGER
N
.TP 17
.ti +4
COMPLEX*16
D( * ), DL( * ), DU( * )
.SH 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.
.SH DESCRIPTION
ZLANGT returns the value
.br
ZLANGT = ( max(abs(A(i,j))), NORM = 'M' or 'm'
.br
(
.br
( norm1(A), NORM = '1', 'O' or 'o'
.br
(
.br
( normI(A), NORM = 'I' or 'i'
.br
(
.br
( 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 matrix norm.
.SH ARGUMENTS
.TP 8
NORM (input) CHARACTER*1
Specifies the value to be returned in ZLANGT as described
above.
.TP 8
N (input) INTEGER
The order of the matrix A. N >= 0. When N = 0, ZLANGT is
set to zero.
.TP 8
DL (input) COMPLEX*16 array, dimension (N-1)
The (n-1) sub-diagonal elements of A.
.TP 8
D (input) COMPLEX*16 array, dimension (N)
The diagonal elements of A.
.TP 8
DU (input) COMPLEX*16 array, dimension (N-1)
The (n-1) super-diagonal elements of A.
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