GNU/Linux |
CentOS 4.8 |
i386 |
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zlanhs(l) |
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ZLANHS - return the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a Hessenberg matrix A
DOUBLE PRECISION |
FUNCTION ZLANHS( NORM, N, A, LDA, WORK ) |
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CHARACTER |
NORM |
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INTEGER |
LDA, N |
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DOUBLE |
PRECISION WORK( * ) |
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COMPLEX*16 |
A( LDA, * ) |
ZLANHS returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a Hessenberg matrix A.
ZLANHS returns the value
ZLANHS = (
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 matrix norm.
NORM (input) CHARACTER*1
Specifies the value to be returned in ZLANHS as described above.
N (input) INTEGER
The order of the matrix A. N >= 0. When N = 0, ZLANHS is set to zero.
A (input) COMPLEX*16 array, dimension (LDA,N)
The n by n upper Hessenberg matrix A; the part of A below the first sub-diagonal is not referenced.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(N,1).
WORK (workspace) DOUBLE PRECISION array, dimension (LWORK),
where LWORK >= N when NORM = ’I’; otherwise, WORK is not referenced.
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zlanhs(l) | ![]() |