From c679afbd8d08c322d8323db5f57e0ab31db0cfca Mon Sep 17 00:00:00 2001
From: jofret
Date: Fri, 11 Apr 2008 09:46:18 +0000
Subject: Adding LAPACK and compilation process

---
 src/lib/lapack/zpotrf.f | 186 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 186 insertions(+)
 create mode 100644 src/lib/lapack/zpotrf.f

(limited to 'src/lib/lapack/zpotrf.f')

diff --git a/src/lib/lapack/zpotrf.f b/src/lib/lapack/zpotrf.f
new file mode 100644
index 00000000..86772608
--- /dev/null
+++ b/src/lib/lapack/zpotrf.f
@@ -0,0 +1,186 @@
+      SUBROUTINE ZPOTRF( UPLO, N, A, LDA, INFO )
+*
+*  -- LAPACK routine (version 3.1) --
+*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
+*     November 2006
+*
+*     .. Scalar Arguments ..
+      CHARACTER          UPLO
+      INTEGER            INFO, LDA, N
+*     ..
+*     .. Array Arguments ..
+      COMPLEX*16         A( LDA, * )
+*     ..
+*
+*  Purpose
+*  =======
+*
+*  ZPOTRF computes the Cholesky factorization of a complex Hermitian
+*  positive definite matrix A.
+*
+*  The factorization has the form
+*     A = U**H * U,  if UPLO = 'U', or
+*     A = L  * L**H,  if UPLO = 'L',
+*  where U is an upper triangular matrix and L is lower triangular.
+*
+*  This is the block version of the algorithm, calling Level 3 BLAS.
+*
+*  Arguments
+*  =========
+*
+*  UPLO    (input) CHARACTER*1
+*          = 'U':  Upper triangle of A is stored;
+*          = 'L':  Lower triangle of A is stored.
+*
+*  N       (input) INTEGER
+*          The order of the matrix A.  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 factor U or L from the Cholesky
+*          factorization A = U**H*U or A = L*L**H.
+*
+*  LDA     (input) INTEGER
+*          The leading dimension of the array A.  LDA >= max(1,N).
+*
+*  INFO    (output) INTEGER
+*          = 0:  successful exit
+*          < 0:  if INFO = -i, the i-th argument had an illegal value
+*          > 0:  if INFO = i, the leading minor of order i is not
+*                positive definite, and the factorization could not be
+*                completed.
+*
+*  =====================================================================
+*
+*     .. Parameters ..
+      DOUBLE PRECISION   ONE
+      COMPLEX*16         CONE
+      PARAMETER          ( ONE = 1.0D+0, CONE = ( 1.0D+0, 0.0D+0 ) )
+*     ..
+*     .. Local Scalars ..
+      LOGICAL            UPPER
+      INTEGER            J, JB, NB
+*     ..
+*     .. External Functions ..
+      LOGICAL            LSAME
+      INTEGER            ILAENV
+      EXTERNAL           LSAME, ILAENV
+*     ..
+*     .. External Subroutines ..
+      EXTERNAL           XERBLA, ZGEMM, ZHERK, ZPOTF2, ZTRSM
+*     ..
+*     .. Intrinsic Functions ..
+      INTRINSIC          MAX, MIN
+*     ..
+*     .. Executable Statements ..
+*
+*     Test the input parameters.
+*
+      INFO = 0
+      UPPER = LSAME( UPLO, 'U' )
+      IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
+         INFO = -1
+      ELSE IF( N.LT.0 ) THEN
+         INFO = -2
+      ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
+         INFO = -4
+      END IF
+      IF( INFO.NE.0 ) THEN
+         CALL XERBLA( 'ZPOTRF', -INFO )
+         RETURN
+      END IF
+*
+*     Quick return if possible
+*
+      IF( N.EQ.0 )
+     $   RETURN
+*
+*     Determine the block size for this environment.
+*
+      NB = ILAENV( 1, 'ZPOTRF', UPLO, N, -1, -1, -1 )
+      IF( NB.LE.1 .OR. NB.GE.N ) THEN
+*
+*        Use unblocked code.
+*
+         CALL ZPOTF2( UPLO, N, A, LDA, INFO )
+      ELSE
+*
+*        Use blocked code.
+*
+         IF( UPPER ) THEN
+*
+*           Compute the Cholesky factorization A = U'*U.
+*
+            DO 10 J = 1, N, NB
+*
+*              Update and factorize the current diagonal block and test
+*              for non-positive-definiteness.
+*
+               JB = MIN( NB, N-J+1 )
+               CALL ZHERK( 'Upper', 'Conjugate transpose', JB, J-1,
+     $                     -ONE, A( 1, J ), LDA, ONE, A( J, J ), LDA )
+               CALL ZPOTF2( 'Upper', JB, A( J, J ), LDA, INFO )
+               IF( INFO.NE.0 )
+     $            GO TO 30
+               IF( J+JB.LE.N ) THEN
+*
+*                 Compute the current block row.
+*
+                  CALL ZGEMM( 'Conjugate transpose', 'No transpose', JB,
+     $                        N-J-JB+1, J-1, -CONE, A( 1, J ), LDA,
+     $                        A( 1, J+JB ), LDA, CONE, A( J, J+JB ),
+     $                        LDA )
+                  CALL ZTRSM( 'Left', 'Upper', 'Conjugate transpose',
+     $                        'Non-unit', JB, N-J-JB+1, CONE, A( J, J ),
+     $                        LDA, A( J, J+JB ), LDA )
+               END IF
+   10       CONTINUE
+*
+         ELSE
+*
+*           Compute the Cholesky factorization A = L*L'.
+*
+            DO 20 J = 1, N, NB
+*
+*              Update and factorize the current diagonal block and test
+*              for non-positive-definiteness.
+*
+               JB = MIN( NB, N-J+1 )
+               CALL ZHERK( 'Lower', 'No transpose', JB, J-1, -ONE,
+     $                     A( J, 1 ), LDA, ONE, A( J, J ), LDA )
+               CALL ZPOTF2( 'Lower', JB, A( J, J ), LDA, INFO )
+               IF( INFO.NE.0 )
+     $            GO TO 30
+               IF( J+JB.LE.N ) THEN
+*
+*                 Compute the current block column.
+*
+                  CALL ZGEMM( 'No transpose', 'Conjugate transpose',
+     $                        N-J-JB+1, JB, J-1, -CONE, A( J+JB, 1 ),
+     $                        LDA, A( J, 1 ), LDA, CONE, A( J+JB, J ),
+     $                        LDA )
+                  CALL ZTRSM( 'Right', 'Lower', 'Conjugate transpose',
+     $                        'Non-unit', N-J-JB+1, JB, CONE, A( J, J ),
+     $                        LDA, A( J+JB, J ), LDA )
+               END IF
+   20       CONTINUE
+         END IF
+      END IF
+      GO TO 40
+*
+   30 CONTINUE
+      INFO = INFO + J - 1
+*
+   40 CONTINUE
+      RETURN
+*
+*     End of ZPOTRF
+*
+      END
-- 
cgit