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

Chapter 9 LAPACK Auxiliary Subprograms 665
Compute norm of general tridiagonal matrix SLANGT/DLANGT/CLANGT/ZLANGT
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
|).
n The order of the matrix A. n ≥ 0.
dl The n−1 subdiagonal elements of A.
d The diagonal elements of A.
du The n−1 superdiagonal elements of A.
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’.