ZHEGST(l)		LAPACK routine (version	1.1)		    ZHEGST(l)

NAME
  ZHEGST - reduce a complex Hermitian-definite generalized eigenproblem	to
  standard form

SYNOPSIS

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

      CHARACTER	     UPLO

      INTEGER	     INFO, ITYPE, LDA, LDB, N

      COMPLEX*16     A(	LDA, * ), B( LDB, * )

PURPOSE
  ZHEGST reduces a complex Hermitian-definite generalized eigenproblem to
  standard form.

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

  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**H or	L**H*A*L.

  B must have been previously factorized as U**H*U or L*L**H by	ZPOTRF.

ARGUMENTS

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

  UPLO	  (input) CHARACTER
	  = 'U':  Upper	triangle of A is stored	and B is factored as U**H*U;
	  = 'L':  Lower	triangle of A is stored	and B is factored as L*L**H.

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

  A	  (input/output) COMPLEX*16 array, dimension (LDA,N)
	  On entry, the	Hermitian 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) COMPLEX*16 array, dimension (LDB,N)
	  The triangular factor	from the Cholesky factorization	of B, as
	  returned by ZPOTRF.

  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