Purpose
To compute the number of zero rows (and zero columns) of a real
(skew-)Hamiltonian matrix,
( A D )
H = ( ).
( E +/-A' )
Specification
INTEGER FUNCTION MA02OD( SKEW, M, A, LDA, DE, LDDE )
C .. Scalar Arguments ..
CHARACTER SKEW
INTEGER LDA, LDDE, M
C .. Array Arguments ..
DOUBLE PRECISION A( LDA, * ), DE( LDDE, * )
Function Value
MA02OD INTEGER
The number of zero rows.
Arguments
Mode Parameters
SKEW CHARACTER*1
Specifies whether the matrix is Hamiltonian or skew-
Hamiltonian as follows:
= 'H': The matrix is Hamiltonian;
= 'S': The matrix is skew-Hamiltonian.
Input/Output Parameters
M (input) INTEGER
The order of the matrices A, D, and E. M >= 0.
A (input) DOUBLE PRECISION array, dimension (LDA,M)
The leading M-by-M part of this array must contain the
matrix A.
LDA INTEGER
The leading dimension of the array A. LDA >= max(1,M).
DE (input) DOUBLE PRECISION array, dimension (LDDE,M+1)
The leading M-by-M lower triangular part of this array
must contain the lower triangular part of the (skew-)
symmetric matrix E, and the M-by-M upper triangular
part of the submatrix in the columns 2 to M+1 of this
array must contain the upper triangular part of the
(skew-)symmetric matrix D. If S is skew-Hamiltonian, the
parts containing the diagonal and the first superdiagonal
of this array, which should be zero, are not referenced.
LDDE INTEGER
The leading dimension of the array DE. LDDE >= MAX(1,M).
Further Comments
NoneExample
Program Text
NoneProgram Data
NoneProgram Results
None