clanht3lapack

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 hermitian tridiagonal matrix a

Usage

REAL FUNCTION: CLANHT( NORM, N, D, E )

CHARACTER: NORM

INTEGER: N

REAL: D( * )

COMPLEX: E( * )

Purpose

CLANHT 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 Hermitian tridiagonal matrix A.

Overview

CLANHT returns the value

CLANHT = ( 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.

Arguments

`NORM (input) CHARACTER*1`	Specifies the value to be returned in CLANHT as described above.
`N (input) INTEGER`	The order of the matrix A. N >= 0. When N = 0, CLANHT is set to zero.
`D (input) REAL array, dimension (N)`	The diagonal elements of A.
`E (input) COMPLEX array, dimension (N-1)`	The (n-1) sub-diagonal or super-diagonal elements of A.