*> \brief \b ZHESWAPR applies an elementary permutation on the rows and columns of a Hermitian matrix. * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * *> \htmlonly *> Download ZHESWAPR + dependencies *> *> [TGZ] *> *> [ZIP] *> *> [TXT] *> \endhtmlonly * * Definition: * =========== * * SUBROUTINE ZHESWAPR( UPLO, N, A, LDA, I1, I2) * * .. Scalar Arguments .. * CHARACTER UPLO * INTEGER I1, I2, LDA, N * .. * .. Array Arguments .. * COMPLEX*16 A( LDA, N ) * * *> \par Purpose: * ============= *> *> \verbatim *> *> ZHESWAPR applies an elementary permutation on the rows and the columns of *> a hermitian matrix. *> \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**T; *> = 'L': Lower triangular, form is A = L*D*L**T. *> \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 NB diagonal matrix D and the multipliers *> used to obtain the factor U or L as computed by CSYTRF. *> *> 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] I1 *> \verbatim *> I1 is INTEGER *> Index of the first row to swap *> \endverbatim *> *> \param[in] I2 *> \verbatim *> I2 is INTEGER *> Index of the second row to swap *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup complex16HEauxiliary * * ===================================================================== SUBROUTINE ZHESWAPR( UPLO, N, A, LDA, I1, I2) * * -- LAPACK auxiliary routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * * .. Scalar Arguments .. CHARACTER UPLO INTEGER I1, I2, LDA, N * .. * .. Array Arguments .. COMPLEX*16 A( LDA, N ) * * ===================================================================== * * .. * .. Local Scalars .. LOGICAL UPPER INTEGER I COMPLEX*16 TMP * * .. External Functions .. LOGICAL LSAME EXTERNAL LSAME * .. * .. External Subroutines .. EXTERNAL ZSWAP * .. * .. Executable Statements .. * UPPER = LSAME( UPLO, 'U' ) IF (UPPER) THEN * * UPPER * first swap * - swap column I1 and I2 from I1 to I1-1 CALL ZSWAP( I1-1, A(1,I1), 1, A(1,I2), 1 ) * * second swap : * - swap A(I1,I1) and A(I2,I2) * - swap row I1 from I1+1 to I2-1 with col I2 from I1+1 to I2-1 * - swap A(I2,I1) and A(I1,I2) TMP=A(I1,I1) A(I1,I1)=A(I2,I2) A(I2,I2)=TMP * DO I=1,I2-I1-1 TMP=A(I1,I1+I) A(I1,I1+I)=DCONJG(A(I1+I,I2)) A(I1+I,I2)=DCONJG(TMP) END DO * A(I1,I2)=DCONJG(A(I1,I2)) * * third swap * - swap row I1 and I2 from I2+1 to N DO I=I2+1,N TMP=A(I1,I) A(I1,I)=A(I2,I) A(I2,I)=TMP END DO * ELSE * * LOWER * first swap * - swap row I1 and I2 from 1 to I1-1 CALL ZSWAP ( I1-1, A(I1,1), LDA, A(I2,1), LDA ) * * second swap : * - swap A(I1,I1) and A(I2,I2) * - swap col I1 from I1+1 to I2-1 with row I2 from I1+1 to I2-1 * - swap A(I2,I1) and A(I1,I2) TMP=A(I1,I1) A(I1,I1)=A(I2,I2) A(I2,I2)=TMP * DO I=1,I2-I1-1 TMP=A(I1+I,I1) A(I1+I,I1)=DCONJG(A(I2,I1+I)) A(I2,I1+I)=DCONJG(TMP) END DO * A(I2,I1)=DCONJG(A(I2,I1)) * * third swap * - swap col I1 and I2 from I2+1 to N DO I=I2+1,N TMP=A(I,I1) A(I,I1)=A(I,I2) A(I,I2)=TMP END DO * ENDIF END SUBROUTINE ZHESWAPR