ZPTTRS(3F)							    ZPTTRS(3F)

NAME    [Toc]    [Back]

     ZPTTRS - solve a system of	linear equations A * X = B with	a Hermitian
     positive definite tridiagonal matrix A using the factorization A =
     U**H*D*U or A = L*D*L**H computed by ZPTTRF

SYNOPSIS    [Toc]    [Back]

     SUBROUTINE	ZPTTRS(	UPLO, N, NRHS, D, E, B,	LDB, INFO )

	 CHARACTER	UPLO

	 INTEGER	INFO, LDB, N, NRHS

	 DOUBLE		PRECISION D( * )

	 COMPLEX*16	B( LDB,	* ), E(	* )

PURPOSE    [Toc]    [Back]

     ZPTTRS solves a system of linear equations	A * X =	B with a Hermitian
     positive definite tridiagonal matrix A using the factorization A =
     U**H*D*U or A = L*D*L**H computed by ZPTTRF.

ARGUMENTS    [Toc]    [Back]

     UPLO    (input) CHARACTER*1
	     Specifies whether the superdiagonal or the	subdiagonal of the
	     tridiagonal matrix	A is stored and	the form of the	factorization:
	     = 'U':  E is the superdiagonal of U, and A	= U'*D*U;
	     = 'L':  E is the subdiagonal of L,	and A =	L*D*L'.	 (The two
	     forms are equivalent if A is real.)

     N	     (input) INTEGER
	     The order of the tridiagonal matrix A.  N >= 0.

     NRHS    (input) INTEGER
	     The number	of right hand sides, i.e., the number of columns of
	     the matrix	B.  NRHS >= 0.

     D	     (input) DOUBLE PRECISION array, dimension (N)
	     The n diagonal elements of	the diagonal matrix D from the
	     factorization computed by ZPTTRF.

     E	     (input) COMPLEX*16	array, dimension (N-1)
	     The (n-1) off-diagonal elements of	the unit bidiagonal factor U
	     or	L from the factorization computed by ZPTTRF (see UPLO).

     B	     (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
	     On	entry, the right hand side matrix B.  On exit, the solution
	     matrix X.

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




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ZPTTRS(3F)							    ZPTTRS(3F)



     INFO    (output) INTEGER
	     = 0:  successful exit
	     < 0:  if INFO = -i, the i-th argument had an illegal value
ZPTTRS(3F)							    ZPTTRS(3F)

NAME    [Toc]    [Back]

     ZPTTRS - solve a system of	linear equations A * X = B with	a Hermitian
     positive definite tridiagonal matrix A using the factorization A =
     U**H*D*U or A = L*D*L**H computed by ZPTTRF

SYNOPSIS    [Toc]    [Back]

     SUBROUTINE	ZPTTRS(	UPLO, N, NRHS, D, E, B,	LDB, INFO )

	 CHARACTER	UPLO

	 INTEGER	INFO, LDB, N, NRHS

	 DOUBLE		PRECISION D( * )

	 COMPLEX*16	B( LDB,	* ), E(	* )

PURPOSE    [Toc]    [Back]

     ZPTTRS solves a system of linear equations	A * X =	B with a Hermitian
     positive definite tridiagonal matrix A using the factorization A =
     U**H*D*U or A = L*D*L**H computed by ZPTTRF.

ARGUMENTS    [Toc]    [Back]

     UPLO    (input) CHARACTER*1
	     Specifies whether the superdiagonal or the	subdiagonal of the
	     tridiagonal matrix	A is stored and	the form of the	factorization:
	     = 'U':  E is the superdiagonal of U, and A	= U'*D*U;
	     = 'L':  E is the subdiagonal of L,	and A =	L*D*L'.	 (The two
	     forms are equivalent if A is real.)

     N	     (input) INTEGER
	     The order of the tridiagonal matrix A.  N >= 0.

     NRHS    (input) INTEGER
	     The number	of right hand sides, i.e., the number of columns of
	     the matrix	B.  NRHS >= 0.

     D	     (input) DOUBLE PRECISION array, dimension (N)
	     The n diagonal elements of	the diagonal matrix D from the
	     factorization computed by ZPTTRF.

     E	     (input) COMPLEX*16	array, dimension (N-1)
	     The (n-1) off-diagonal elements of	the unit bidiagonal factor U
	     or	L from the factorization computed by ZPTTRF (see UPLO).

     B	     (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
	     On	entry, the right hand side matrix B.  On exit, the solution
	     matrix X.

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




									Page 1






ZPTTRS(3F)							    ZPTTRS(3F)



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


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