HP MLIB User's Guide Vol. 2 7th Ed.

662 HP MLIB LAPACK User’s Guide
SLANGE/DLANGE/CLANGE/ZLANGE Compute norm of general matrix
CHARACTER*1 norm
INTEGER*8 lda, m, n
REAL*4 rwork(n)
COMPLEX*8 a(lda, n)
REAL*4 anorm, CLANGE
anorm = CLANGE(norm, m, n, a, lda, rwork)
CHARACTER*1 norm
INTEGER*8 lda, m, n
REAL*8 rwork(n)
COMPLEX*16 a(lda, n)
REAL*8 anorm, ZLANGE
anorm = ZLANGE(norm, m, n, a, lda, rwork)
Input norm Specifies which norm is to be computed, as follows:
norm = ’F’, ’f’, ’E’, or ’e’ Compute ||A||
F
= the Frobenius
norm.
norm = ’I’ or ’i’ Compute ||A||
∞
= maximum
row sum.
norm = ’1’, ’O’, or ’o’ Compute ||A||
1
= maximum
column sum.
norm = ’M’ or ’m’ Compute max(|A
ij
|).
m The number of rows of the matrix A. n ≥ 0.
n The number of columns of the matrix A. n ≥ 0.
a The m-by-n matrix A.
lda The leading dimension of array a in the calling
program unit. lda ≥ max(1,m).
Working
Storage
work,
rwork
Arrays used for work space. Not referenced unless
norm = ’I’ or ’i’.
Output anorm The function value is the value of the requested norm
of A.
Notes Actual character arguments in a subroutine call may be longer than the
corresponding dummy arguments. Therefore, readability of the CALL
statement may be improved by coding the norm argument as ’Frobenius’ for ’F’,
’Infinity-Norm’ for ’I’, ’One-norm’ or ’1-norm’ for ’O’, or ’Max-Element’ for ’M’.