👤
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 dggbak (redhat section l)

DGGBAK(l)					)					DGGBAK(l)

NAME
       DGGBAK  - form the right or left eigenvectors of a real generalized eigenvalue problem A*x
       = lambda*B*x, by backward transformation on the computed eigenvectors of the balanced pair
       of matrices output by DGGBAL

SYNOPSIS
       SUBROUTINE DGGBAK( JOB, SIDE, N, ILO, IHI, LSCALE, RSCALE, M, V, LDV, INFO )

	   CHARACTER	  JOB, SIDE

	   INTEGER	  IHI, ILO, INFO, LDV, M, N

	   DOUBLE	  PRECISION LSCALE( * ), RSCALE( * ), V( LDV, * )

PURPOSE
       DGGBAK forms the right or left eigenvectors of a real generalized eigenvalue problem A*x =
       lambda*B*x, by backward transformation on the computed eigenvectors of the  balanced  pair
       of matrices output by DGGBAL.

ARGUMENTS
       JOB     (input) CHARACTER*1
	       Specifies the type of backward transformation required:
	       = 'N':  do nothing, return immediately;
	       = 'P':  do backward transformation for permutation only;
	       = 'S':  do backward transformation for scaling only;
	       = 'B':  do backward transformations for both permutation and scaling.  JOB must be
	       the same as the argument JOB supplied to DGGBAL.

       SIDE    (input) CHARACTER*1
	       = 'R':  V contains right eigenvectors;
	       = 'L':  V contains left eigenvectors.

       N       (input) INTEGER
	       The number of rows of the matrix V.  N >= 0.

       ILO     (input) INTEGER
	       IHI     (input) INTEGER The integers ILO and IHI determined by DGGBAL.  1  <=  ILO
	       <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

       LSCALE  (input) DOUBLE PRECISION array, dimension (N)
	       Details	of  the permutations and/or scaling factors applied to the left side of A
	       and B, as returned by DGGBAL.

       RSCALE  (input) DOUBLE PRECISION array, dimension (N)
	       Details of the permutations and/or scaling factors applied to the right side of	A
	       and B, as returned by DGGBAL.

       M       (input) INTEGER
	       The number of columns of the matrix V.  M >= 0.

       V       (input/output) DOUBLE PRECISION array, dimension (LDV,M)
	       On  entry, the matrix of right or left eigenvectors to be transformed, as returned
	       by DTGEVC.  On exit, V is overwritten by the transformed eigenvectors.

       LDV     (input) INTEGER
	       The leading dimension of the matrix V. LDV >= max(1,N).

       INFO    (output) INTEGER
	       = 0:  successful exit.
	       < 0:  if INFO = -i, the i-th argument had an illegal value.

FURTHER DETAILS
       See R.C. Ward, Balancing the generalized eigenvalue problem,
		      SIAM J. Sci. Stat. Comp. 2 (1981), 141-152.

LAPACK version 3.0			   15 June 2000 				DGGBAK(l)


All times are GMT -4. The time now is 08:39 PM.

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