--- rpl/lapack/lapack/zhetri2x.f 2011/07/24 10:31:39 1.1 +++ rpl/lapack/lapack/zhetri2x.f 2023/08/07 08:39:25 1.13 @@ -1,11 +1,126 @@ +*> \brief \b ZHETRI2X +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +*> \htmlonly +*> Download ZHETRI2X + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE ZHETRI2X( UPLO, N, A, LDA, IPIV, WORK, NB, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER UPLO +* INTEGER INFO, LDA, N, NB +* .. +* .. Array Arguments .. +* INTEGER IPIV( * ) +* COMPLEX*16 A( LDA, * ), WORK( N+NB+1,* ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> ZHETRI2X computes the inverse of a COMPLEX*16 Hermitian indefinite matrix +*> A using the factorization A = U*D*U**H or A = L*D*L**H computed by +*> ZHETRF. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> Specifies whether the details of the factorization are stored +*> as an upper or lower triangular matrix. +*> = 'U': Upper triangular, form is A = U*D*U**H; +*> = 'L': Lower triangular, form is A = L*D*L**H. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in,out] A +*> \verbatim +*> A is COMPLEX*16 array, dimension (LDA,N) +*> On entry, the NNB diagonal matrix D and the multipliers +*> used to obtain the factor U or L as computed by ZHETRF. +*> +*> On exit, if INFO = 0, the (symmetric) inverse of the original +*> matrix. If UPLO = 'U', the upper triangular part of the +*> inverse is formed and the part of A below the diagonal is not +*> referenced; if UPLO = 'L' the lower triangular part of the +*> inverse is formed and the part of A above the diagonal is +*> not referenced. +*> \endverbatim +*> +*> \param[in] LDA +*> \verbatim +*> LDA is INTEGER +*> The leading dimension of the array A. LDA >= max(1,N). +*> \endverbatim +*> +*> \param[in] IPIV +*> \verbatim +*> IPIV is INTEGER array, dimension (N) +*> Details of the interchanges and the NNB structure of D +*> as determined by ZHETRF. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is COMPLEX*16 array, dimension (N+NB+1,NB+3) +*> \endverbatim +*> +*> \param[in] NB +*> \verbatim +*> NB is INTEGER +*> Block size +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its +*> inverse could not be computed. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \ingroup complex16HEcomputational +* +* ===================================================================== SUBROUTINE ZHETRI2X( UPLO, N, A, LDA, IPIV, WORK, NB, INFO ) * -* -- LAPACK routine (version 3.3.1) -- +* -- LAPACK computational routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* -- April 2011 -- -* -* -- Written by Julie Langou of the Univ. of TN -- * * .. Scalar Arguments .. CHARACTER UPLO @@ -16,58 +131,10 @@ COMPLEX*16 A( LDA, * ), WORK( N+NB+1,* ) * .. * -* Purpose -* ======= -* -* ZHETRI2X computes the inverse of a COMPLEX*16 Hermitian indefinite matrix -* A using the factorization A = U*D*U**H or A = L*D*L**H computed by -* ZHETRF. -* -* Arguments -* ========= -* -* UPLO (input) CHARACTER*1 -* Specifies whether the details of the factorization are stored -* as an upper or lower triangular matrix. -* = 'U': Upper triangular, form is A = U*D*U**H; -* = 'L': Lower triangular, form is A = L*D*L**H. -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* A (input/output) COMPLEX*16 array, dimension (LDA,N) -* On entry, the NNB diagonal matrix D and the multipliers -* used to obtain the factor U or L as computed by ZHETRF. -* -* On exit, if INFO = 0, the (symmetric) inverse of the original -* matrix. If UPLO = 'U', the upper triangular part of the -* inverse is formed and the part of A below the diagonal is not -* referenced; if UPLO = 'L' the lower triangular part of the -* inverse is formed and the part of A above the diagonal is -* not referenced. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1,N). -* -* IPIV (input) INTEGER array, dimension (N) -* Details of the interchanges and the NNB structure of D -* as determined by ZHETRF. -* -* WORK (workspace) COMPLEX*16 array, dimension (N+NNB+1,NNB+3) -* -* NB (input) INTEGER -* Block size -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its -* inverse could not be computed. -* * ===================================================================== * * .. Parameters .. - REAL ONE + DOUBLE PRECISION ONE COMPLEX*16 CONE, ZERO PARAMETER ( ONE = 1.0D+0, $ CONE = ( 1.0D+0, 0.0D+0 ), @@ -145,7 +212,7 @@ INFO = 0 * * Splitting Workspace -* U01 is a block (N,NB+1) +* U01 is a block (N,NB+1) * The first element of U01 is in WORK(1,1) * U11 is a block (NB+1,NB+1) * The first element of U11 is in WORK(N+1,1) @@ -161,7 +228,7 @@ CALL ZTRTRI( UPLO, 'U', N, A, LDA, INFO ) * * inv(D) and inv(D)*inv(U) -* +* K=1 DO WHILE ( K .LE. N ) IF( IPIV( K ).GT.0 ) THEN @@ -172,13 +239,13 @@ ELSE * 2 x 2 diagonal NNB T = ABS ( WORK(K+1,1) ) - AK = REAL ( A( K, K ) ) / T - AKP1 = REAL ( A( K+1, K+1 ) ) / T + AK = DBLE ( A( K, K ) ) / T + AKP1 = DBLE ( A( K+1, K+1 ) ) / T AKKP1 = WORK(K+1,1) / T D = T*( AK*AKP1-ONE ) WORK(K,INVD) = AKP1 / D WORK(K+1,INVD+1) = AK / D - WORK(K,INVD+1) = -AKKP1 / D + WORK(K,INVD+1) = -AKKP1 / D WORK(K+1,INVD) = DCONJG (WORK(K,INVD+1) ) K=K+2 END IF @@ -195,7 +262,7 @@ NNB=CUT ELSE COUNT = 0 -* count negative elements, +* count negative elements, DO I=CUT+1-NNB,CUT IF (IPIV(I) .LT. 0) COUNT=COUNT+1 END DO @@ -205,7 +272,7 @@ CUT=CUT-NNB * -* U01 Block +* U01 Block * DO I=1,CUT DO J=1,NNB @@ -268,7 +335,7 @@ I=I+2 END IF END DO -* +* * U11**H*invD1*U11->U11 * CALL ZTRMM('L','U','C','U',NNB, NNB, @@ -312,7 +379,7 @@ END DO * * Apply PERMUTATIONS P and P**H: P * inv(U**H)*inv(D)*inv(U) *P**H -* +* I=1 DO WHILE ( I .LE. N ) IF( IPIV(I) .GT. 0 ) THEN @@ -322,9 +389,9 @@ ELSE IP=-IPIV(I) I=I+1 - IF ( (I-1) .LT. IP) + IF ( (I-1) .LT. IP) $ CALL ZHESWAPR( UPLO, N, A, LDA, I-1 ,IP ) - IF ( (I-1) .GT. IP) + IF ( (I-1) .GT. IP) $ CALL ZHESWAPR( UPLO, N, A, LDA, IP ,I-1 ) ENDIF I=I+1 @@ -338,7 +405,7 @@ CALL ZTRTRI( UPLO, 'U', N, A, LDA, INFO ) * * inv(D) and inv(D)*inv(U) -* +* K=N DO WHILE ( K .GE. 1 ) IF( IPIV( K ).GT.0 ) THEN @@ -349,13 +416,13 @@ ELSE * 2 x 2 diagonal NNB T = ABS ( WORK(K-1,1) ) - AK = REAL ( A( K-1, K-1 ) ) / T - AKP1 = REAL ( A( K, K ) ) / T + AK = DBLE ( A( K-1, K-1 ) ) / T + AKP1 = DBLE ( A( K, K ) ) / T AKKP1 = WORK(K-1,1) / T D = T*( AK*AKP1-ONE ) WORK(K-1,INVD) = AKP1 / D WORK(K,INVD) = AK / D - WORK(K,INVD+1) = -AKKP1 / D + WORK(K,INVD+1) = -AKKP1 / D WORK(K-1,INVD+1) = DCONJG (WORK(K,INVD+1) ) K=K-2 END IF @@ -372,7 +439,7 @@ NNB=N-CUT ELSE COUNT = 0 -* count negative elements, +* count negative elements, DO I=CUT+1,CUT+NNB IF (IPIV(I) .LT. 0) COUNT=COUNT+1 END DO @@ -439,7 +506,7 @@ I=I-2 END IF END DO -* +* * L11**H*invD1*L11->L11 * CALL ZTRMM('L',UPLO,'C','U',NNB, NNB, @@ -457,7 +524,7 @@ * CALL ZGEMM('C','N',NNB,NNB,N-NNB-CUT,CONE,A(CUT+NNB+1,CUT+1) $ ,LDA,WORK,N+NB+1, ZERO, WORK(U11+1,1), N+NB+1) - + * * L11 = L11**H*invD1*L11 + U01**H*invD*U01 * @@ -495,7 +562,7 @@ END DO * * Apply PERMUTATIONS P and P**H: P * inv(U**H)*inv(D)*inv(U) *P**H -* +* I=N DO WHILE ( I .GE. 1 ) IF( IPIV(I) .GT. 0 ) THEN