👤
Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

RedHat 9 (Linux i386) - man page for ctgex2 (redhat section l)

CTGEX2(l)					)					CTGEX2(l)

NAME
       CTGEX2 - swap adjacent diagonal 1 by 1 blocks (A11,B11) and (A22,B22)

SYNOPSIS
       SUBROUTINE CTGEX2( WANTQ, WANTZ, N, A, LDA, B, LDB, Q, LDQ, Z, LDZ, J1, INFO )

	   LOGICAL	  WANTQ, WANTZ

	   INTEGER	  INFO, J1, LDA, LDB, LDQ, LDZ, N

	   COMPLEX	  A( LDA, * ), B( LDB, * ), Q( LDQ, * ), Z( LDZ, * )

PURPOSE
       CTGEX2  swaps adjacent diagonal 1 by 1 blocks (A11,B11) and (A22,B22) in an upper triangu-
       lar matrix pair (A, B) by an unitary equivalence transformation.

       (A, B) must be in generalized Schur canonical form, that is, A and B are both upper trian-
       gular.

       Optionally, the matrices Q and Z of generalized Schur vectors are updated.

	      Q(in) * A(in) * Z(in)' = Q(out) * A(out) * Z(out)'
	      Q(in) * B(in) * Z(in)' = Q(out) * B(out) * Z(out)'

ARGUMENTS
       WANTQ   (input) LOGICAL

       WANTZ   (input) LOGICAL

       N       (input) INTEGER
	       The order of the matrices A and B. N >= 0.

       A       (input/output) COMPLEX arrays, dimensions (LDA,N)
	       On entry, the matrix A in the pair (A, B).  On exit, the updated matrix A.

       LDA     (input)	INTEGER
	       The leading dimension of the array A. LDA >= max(1,N).

       B       (input/output) COMPLEX arrays, dimensions (LDB,N)
	       On entry, the matrix B in the pair (A, B).  On exit, the updated matrix B.

       LDB     (input)	INTEGER
	       The leading dimension of the array B. LDB >= max(1,N).

       Q       (input/output) COMPLEX array, dimension (LDZ,N)
	       If  WANTQ  = .TRUE, on entry, the unitary matrix Q. On exit, the updated matrix Q.
	       Not referenced if WANTQ = .FALSE..

       LDQ     (input) INTEGER
	       The leading dimension of the array Q. LDQ >= 1; If WANTQ = .TRUE., LDQ >= N.

       Z       (input/output) COMPLEX array, dimension (LDZ,N)
	       If WANTZ = .TRUE, on entry, the unitary matrix Z. On exit, the updated  matrix  Z.
	       Not referenced if WANTZ = .FALSE..

       LDZ     (input) INTEGER
	       The leading dimension of the array Z. LDZ >= 1; If WANTZ = .TRUE., LDZ >= N.

       J1      (input) INTEGER
	       The index to the first block (A11, B11).

       INFO    (output) INTEGER
	       =0:  Successful exit.
	       =1:   The  transformed  matrix pair (A, B) would be too far from generalized Schur
	       form; the problem is ill- conditioned. (A, B) may have been  partially  reordered,
	       and ILST points to the first row of the current position of the block being moved.

FURTHER DETAILS
       Based on contributions by
	  Bo Kagstrom and Peter Poromaa, Department of Computing Science,
	  Umea University, S-901 87 Umea, Sweden.

       In  the current code both weak and strong stability tests are performed. The user can omit
       the strong stability test by changing the internal logical parameter WANDS to .FALSE.. See
       ref. [2] for details.

       [1] B. Kagstrom; A Direct Method for Reordering Eigenvalues in the
	   Generalized Real Schur Form of a Regular Matrix Pair (A, B), in
	   M.S. Moonen et al (eds), Linear Algebra for Large Scale and
	   Real-Time Applications, Kluwer Academic Publ. 1993, pp 195-218.

       [2] B. Kagstrom and P. Poromaa; Computing Eigenspaces with Specified
	   Eigenvalues of a Regular Matrix Pair (A, B) and Condition
	   Estimation: Theory, Algorithms and Software, Report UMINF-94.04,
	   Department of Computing Science, Umea University, S-901 87 Umea,
	   Sweden, 1994. Also as LAPACK Working Note 87. To appear in
	   Numerical Algorithms, 1996.

LAPACK version 3.0			   15 June 2000 				CTGEX2(l)


All times are GMT -4. The time now is 10:00 PM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password