--- rpl/lapack/lapack/zhetrs2.f 2010/12/21 13:50:37 1.1 +++ rpl/lapack/lapack/zhetrs2.f 2017/06/17 11:06:49 1.12 @@ -1,13 +1,136 @@ - SUBROUTINE ZHETRS2( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, - $ WORK, INFO ) +*> \brief \b ZHETRS2 +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ * -* -- LAPACK PROTOTYPE routine (version 3.3.0) -- +*> \htmlonly +*> Download ZHETRS2 + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE ZHETRS2( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, +* WORK, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER UPLO +* INTEGER INFO, LDA, LDB, N, NRHS +* .. +* .. Array Arguments .. +* INTEGER IPIV( * ) +* COMPLEX*16 A( LDA, * ), B( LDB, * ), WORK( * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> ZHETRS2 solves a system of linear equations A*X = B with a complex +*> Hermitian matrix A using the factorization A = U*D*U**H or +*> A = L*D*L**H computed by ZHETRF and converted by ZSYCONV. +*> \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] NRHS +*> \verbatim +*> NRHS is INTEGER +*> The number of right hand sides, i.e., the number of columns +*> of the matrix B. NRHS >= 0. +*> \endverbatim +*> +*> \param[in] A +*> \verbatim +*> A is COMPLEX*16 array, dimension (LDA,N) +*> The block diagonal matrix D and the multipliers used to +*> obtain the factor U or L as computed by ZHETRF. +*> \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 block structure of D +*> as determined by ZHETRF. +*> \endverbatim +*> +*> \param[in,out] B +*> \verbatim +*> B is COMPLEX*16 array, dimension (LDB,NRHS) +*> On entry, the right hand side matrix B. +*> On exit, the solution matrix X. +*> \endverbatim +*> +*> \param[in] LDB +*> \verbatim +*> LDB is INTEGER +*> The leading dimension of the array B. LDB >= max(1,N). +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is COMPLEX*16 array, dimension (N) +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. * -* -- Written by Julie Langou of the Univ. of TN -- -* November 2010 +*> \date June 2016 +* +*> \ingroup complex16HEcomputational +* +* ===================================================================== + SUBROUTINE ZHETRS2( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, + $ WORK, INFO ) * +* -- LAPACK computational routine (version 3.7.0) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* June 2016 * * .. Scalar Arguments .. CHARACTER UPLO @@ -15,74 +138,27 @@ * .. * .. Array Arguments .. INTEGER IPIV( * ) - DOUBLE COMPLEX A( LDA, * ), B( LDB, * ), WORK( * ) + COMPLEX*16 A( LDA, * ), B( LDB, * ), WORK( * ) * .. * -* Purpose -* ======= -* -* ZHETRS2 solves a system of linear equations A*X = B with a real -* Hermitian matrix A using the factorization A = U*D*U**T or -* A = L*D*L**T computed by ZSYTRF and converted by ZSYCONV. -* -* 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. -* -* NRHS (input) INTEGER -* The number of right hand sides, i.e., the number of columns -* of the matrix B. NRHS >= 0. -* -* A (input) DOUBLE COMPLEX array, dimension (LDA,N) -* The block diagonal matrix D and the multipliers used to -* obtain the factor U or L as computed by ZHETRF. -* -* 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 block structure of D -* as determined by ZHETRF. -* -* B (input/output) DOUBLE COMPLEX 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). -* -* WORK (workspace) REAL array, dimension (N) -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* * ===================================================================== * * .. Parameters .. - DOUBLE COMPLEX ONE + COMPLEX*16 ONE PARAMETER ( ONE = (1.0D+0,0.0D+0) ) * .. * .. Local Scalars .. LOGICAL UPPER INTEGER I, IINFO, J, K, KP DOUBLE PRECISION S - DOUBLE COMPLEX AK, AKM1, AKM1K, BK, BKM1, DENOM + COMPLEX*16 AK, AKM1, AKM1K, BK, BKM1, DENOM * .. * .. External Functions .. LOGICAL LSAME EXTERNAL LSAME * .. * .. External Subroutines .. - EXTERNAL ZLACGV, ZSCAL, ZSYCONV, ZSWAP, ZTRSM, XERBLA + EXTERNAL ZDSCAL, ZSYCONV, ZSWAP, ZTRSM, XERBLA * .. * .. Intrinsic Functions .. INTRINSIC DBLE, DCONJG, MAX @@ -118,9 +194,9 @@ * IF( UPPER ) THEN * -* Solve A*X = B, where A = U*D*U'. +* Solve A*X = B, where A = U*D*U**H. * -* P' * B +* P**T * B K=N DO WHILE ( K .GE. 1 ) IF( IPIV( K ).GT.0 ) THEN @@ -140,12 +216,12 @@ END IF END DO * -* Compute (U \P' * B) -> B [ (U \P' * B) ] +* Compute (U \P**T * B) -> B [ (U \P**T * B) ] +* + CALL ZTRSM('L','U','N','U',N,NRHS,ONE,A,LDA,B,LDB) * - CALL ZTRSM('L','U','N','U',N,NRHS,ONE,A,N,B,N) +* Compute D \ B -> B [ D \ (U \P**T * B) ] * -* Compute D \ B -> B [ D \ (U \P' * B) ] -* I=N DO WHILE ( I .GE. 1 ) IF( IPIV(I) .GT. 0 ) THEN @@ -169,11 +245,11 @@ I = I - 1 END DO * -* Compute (U' \ B) -> B [ U' \ (D \ (U \P' * B) ) ] +* Compute (U**H \ B) -> B [ U**H \ (D \ (U \P**T * B) ) ] * - CALL ZTRSM('L','U','C','U',N,NRHS,ONE,A,N,B,N) + CALL ZTRSM('L','U','C','U',N,NRHS,ONE,A,LDA,B,LDB) * -* P * B [ P * (U' \ (D \ (U \P' * B) )) ] +* P * B [ P * (U**H \ (D \ (U \P**T * B) )) ] * K=1 DO WHILE ( K .LE. N ) @@ -196,9 +272,9 @@ * ELSE * -* Solve A*X = B, where A = L*D*L'. +* Solve A*X = B, where A = L*D*L**H. * -* P' * B +* P**T * B K=1 DO WHILE ( K .LE. N ) IF( IPIV( K ).GT.0 ) THEN @@ -218,12 +294,12 @@ ENDIF END DO * -* Compute (L \P' * B) -> B [ (L \P' * B) ] +* Compute (L \P**T * B) -> B [ (L \P**T * B) ] * - CALL ZTRSM('L','L','N','U',N,NRHS,ONE,A,N,B,N) + CALL ZTRSM('L','L','N','U',N,NRHS,ONE,A,LDA,B,LDB) +* +* Compute D \ B -> B [ D \ (L \P**T * B) ] * -* Compute D \ B -> B [ D \ (L \P' * B) ] -* I=1 DO WHILE ( I .LE. N ) IF( IPIV(I) .GT. 0 ) THEN @@ -245,11 +321,11 @@ I = I + 1 END DO * -* Compute (L' \ B) -> B [ L' \ (D \ (L \P' * B) ) ] -* - CALL ZTRSM('L','L','C','U',N,NRHS,ONE,A,N,B,N) +* Compute (L**H \ B) -> B [ L**H \ (D \ (L \P**T * B) ) ] +* + CALL ZTRSM('L','L','C','U',N,NRHS,ONE,A,LDA,B,LDB) * -* P * B [ P * (L' \ (D \ (L \P' * B) )) ] +* P * B [ P * (L**H \ (D \ (L \P**T * B) )) ] * K=N DO WHILE ( K .GE. 1 )