dsygs2.f man page on Oracle

Man page or keyword search:  
man Server   33470 pages
apropos Keyword Search (all sections)
Output format
Oracle logo
[printable version]

dsygs2.f(3)			    LAPACK			   dsygs2.f(3)

NAME
       dsygs2.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dsygs2 (ITYPE, UPLO, N, A, LDA, B, LDB, INFO)
	   DSYGS2 reduces a symmetric definite generalized eigenproblem to
	   standard form, using the factorization results obtained from spotrf
	   (unblocked algorithm).

Function/Subroutine Documentation
   subroutine dsygs2 (integerITYPE, characterUPLO, integerN, double precision,
       dimension( lda, * )A, integerLDA, double precision, dimension( ldb, *
       )B, integerLDB, integerINFO)
       DSYGS2 reduces a symmetric definite generalized eigenproblem to
       standard form, using the factorization results obtained from spotrf
       (unblocked algorithm).

       Purpose:

	    DSYGS2 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 DPOTRF.

       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
		     Specifies whether the upper or lower triangular part of the
		     symmetric matrix A is stored, and how B has been factorized.
		     = 'U':  Upper triangular
		     = 'L':  Lower triangular

	   N

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

	   A

		     A is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (LDB,N)
		     The triangular factor from the Cholesky factorization of B,
		     as returned by DPOTRF.

	   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:
	   September 2012

       Definition at line 128 of file dsygs2.f.

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

Version 3.4.2			Tue Sep 25 2012			   dsygs2.f(3)
[top]

List of man pages available for Oracle

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net