redhat man page for sgebak

SGEBAK(l)								 )								 SGEBAK(l)

NAME
       SGEBAK  -  form the right or left eigenvectors of a real general matrix by backward transformation on the computed eigenvectors of the bal-
       anced matrix output by SGEBAL

SYNOPSIS
       SUBROUTINE SGEBAK( JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO )

	   CHARACTER	  JOB, SIDE

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

	   REAL 	  V( LDV, * ), SCALE( * )

PURPOSE
       SGEBAK forms the right or left eigenvectors of a real general matrix by backward transformation on the computed eigenvectors  of  the  bal-
       anced matrix output by SGEBAL.

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 SGEBAL.

       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 SGEBAL.  1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

       SCALE   (input) REAL array, dimension (N)
	       Details of the permutation and scaling factors, as returned by SGEBAL.

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

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

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

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

LAPACK version 3.0						   15 June 2000 							 SGEBAK(l)