Purpose
To compute the pertranspose of a central band of a square matrix.Specification
SUBROUTINE MA02CD( N, KL, KU, A, LDA )
C .. Scalar Arguments ..
INTEGER KL, KU, LDA, N
C .. Array Arguments ..
DOUBLE PRECISION A(LDA,*)
Arguments
Input/Output Parameters
N (input) INTEGER
The order of the square matrix A. N >= 0.
KL (input) INTEGER
The number of subdiagonals of A to be pertransposed.
0 <= KL <= N-1.
KU (input) INTEGER
The number of superdiagonals of A to be pertransposed.
0 <= KU <= N-1.
A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the leading N-by-N part of this array must
contain a square matrix whose central band formed from
the KL subdiagonals, the main diagonal and the KU
superdiagonals will be pertransposed.
On exit, the leading N-by-N part of this array contains
the matrix A with its central band (the KL subdiagonals,
the main diagonal and the KU superdiagonals) pertransposed
(that is the elements of each antidiagonal appear in
reversed order). This is equivalent to forming P*B'*P,
where B is the matrix formed from the central band of A
and P is a permutation matrix with ones down the secondary
diagonal.
LDA INTEGER
The leading dimension of the array A. LDA >= max(1,N).
Further Comments
NoneExample
Program Text
NoneProgram Data
NoneProgram Results
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