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ssygst.f(3) [debian man page]

ssygst.f(3)							      LAPACK							       ssygst.f(3)

NAME

       ssygst.f -

SYNOPSIS

   Functions/Subroutines
       subroutine ssygst (ITYPE, UPLO, N, A, LDA, B, LDB, INFO)
	   SSYGST

Function/Subroutine Documentation
   subroutine ssygst (integerITYPE, characterUPLO, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( ldb, * )B, integerLDB,
       integerINFO)
       SSYGST

       Purpose:

	    SSYGST reduces a real symmetric-definite generalized eigenproblem
	    to standard form.

	    If ITYPE = 1, the problem is A*x = lambda*B*x,
	    and A is overwritten by inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T)

	    If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or
	    B*A*x = lambda*x, and A is overwritten by U*A*U**T or L**T*A*L.

	    B must have been previously factorized as U**T*U or L*L**T by SPOTRF.

       Parameters:
	   ITYPE

		     ITYPE is INTEGER
		     = 1: compute inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T);
		     = 2 or 3: compute U*A*U**T or L**T*A*L.

	   UPLO

		     UPLO is CHARACTER*1
		     = 'U':  Upper triangle of A is stored and B is factored as
			     U**T*U;
		     = 'L':  Lower triangle of A is stored and B is factored as
			     L*L**T.

	   N

		     N is INTEGER
		     The order of the matrices A and B.  N >= 0.

	   A

		     A is REAL array, dimension (LDA,N)
		     On entry, the symmetric matrix A.	If UPLO = 'U', the leading
		     N-by-N upper triangular part of A contains the upper
		     triangular part of the matrix A, and the strictly lower
		     triangular part of A is not referenced.  If UPLO = 'L', the
		     leading N-by-N lower triangular part of A contains the lower
		     triangular part of the matrix A, and the strictly upper
		     triangular part of A is not referenced.

		     On exit, if INFO = 0, the transformed matrix, stored in the
		     same format as A.

	   LDA

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

	   B

		     B is REAL array, dimension (LDB,N)
		     The triangular factor from the Cholesky factorization of B,
		     as returned by SPOTRF.

	   LDB

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

	   INFO

		     INFO is INTEGER
		     = 0:  successful exit
		     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 128 of file ssygst.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       ssygst.f(3)

Check Out this Related Man Page

SSYGST(l)								 )								 SSYGST(l)

NAME

       SSYGST - reduce a real symmetric-definite generalized eigenproblem to standard form

SYNOPSIS

       SUBROUTINE SSYGST( ITYPE, UPLO, N, A, LDA, B, LDB, INFO )

	   CHARACTER	  UPLO

	   INTEGER	  INFO, ITYPE, LDA, LDB, N

	   REAL 	  A( LDA, * ), B( LDB, * )

PURPOSE

       SSYGST reduces a real symmetric-definite generalized eigenproblem to standard form.  If ITYPE = 1, the problem is A*x = lambda*B*x,
       and A is overwritten by inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T)

       If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or
       B*A*x = lambda*x, and A is overwritten by U*A*U**T or L**T*A*L.

       B must have been previously factorized as U**T*U or L*L**T by SPOTRF.

ARGUMENTS

       ITYPE   (input) INTEGER
	       = 1: compute inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T);
	       = 2 or 3: compute U*A*U**T or L**T*A*L.

       UPLO    (input) CHARACTER
	       =  'U':	 Upper	triangle  of  A  is stored and B is factored as U**T*U; = 'L':	Lower triangle of A is stored and B is factored as
	       L*L**T.

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

       A       (input/output) REAL array, dimension (LDA,N)
	       On entry, the symmetric matrix A.  If UPLO = 'U', the leading N-by-N upper triangular part of A contains the upper triangular  part
	       of the matrix A, and the strictly lower triangular part of A is not referenced.	If UPLO = 'L', the leading N-by-N lower triangular
	       part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced.

	       On exit, if INFO = 0, the transformed matrix, stored in the same format as A.

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

       B       (input) REAL array, dimension (LDB,N)
	       The triangular factor from the Cholesky factorization of B, as returned by SPOTRF.

       LDB     (input) INTEGER
	       The leading dimension of the array B.  LDB >= 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 							 SSYGST(l)
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