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

Chapter 9 LAPACK Auxiliary Subprograms 667

Compute norm of symmetric or Hermitian band matrix SLANSB/DLANSB/CLANHB/CLANSB/ZLANHB/ZLANSB

The asterisks represent elements in the kd-by-kd triangle at the upper left

corner of ab that are not referenced. Thus, if a

is an element within the band of

the upper triangle of A, it is stored in ab(kd+1+i−j,j). Therefore, the columns of

the upper triangle of A are stored in the columns of ab, and the diagonals of the

upper triangle of A are stored in the rows of ab.

Lower triangular storage

The lower triangle of A is stored in the array ab as follows:

The asterisks represent elements in the kd-by-kd triangle at the lower right

corner of ab that are not referenced. Thus, if a

is an element within the band of

the lower triangle of A, it is stored in ab(kd+1+i−j,j). Therefore, the columns of

the lower triangle of A are stored in the columns of ab, and the diagonals of the

lower triangle of A are stored in the rows of ab.

Usage LAPACK:

CHARACTER*1 norm, uplo

INTEGER*4 kd, ldab, n

REAL*4 ab(ldab, n), work(n)

REAL*4 anorm, SLANSB

anorm = SLANSB(norm, uplo, n, kd, ab, ldab, work)

CHARACTER*1 norm, uplo

INTEGER*4 kd, ldab, n

REAL*8 ab(ldab, n), work(n)

REAL*8 anorm, DLANSB

anorm = DLANSB(norm, uplo, n, kd, ab, ldab, work)

CHARACTER*1 norm, uplo

INTEGER*4 kd, ldab, n

REAL*4 rwork(n)

COMPLEX*8 ab(ldab, n)

REAL*4 anorm, CLANHB

anorm = CLANHB(norm, uplo, n, kd, ab, ldab, rwork)

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