Annotation of rpl/lapack/lapack/zheswapr.f, revision 1.1
1.1 ! bertrand 1: SUBROUTINE ZHESWAPR( UPLO, N, A, LDA, I1, I2)
! 2: *
! 3: * -- LAPACK auxiliary routine (version 3.3.1) --
! 4: * -- LAPACK is a software package provided by Univ. of Tennessee, --
! 5: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
! 6: * -- April 2011 --
! 7: *
! 8: * .. Scalar Arguments ..
! 9: CHARACTER UPLO
! 10: INTEGER I1, I2, LDA, N
! 11: * ..
! 12: * .. Array Arguments ..
! 13: COMPLEX*16 A( LDA, N )
! 14: *
! 15: * Purpose
! 16: * =======
! 17: *
! 18: * ZHESWAPR applies an elementary permutation on the rows and the columns of
! 19: * a hermitian matrix.
! 20: *
! 21: * Arguments
! 22: * =========
! 23: *
! 24: * UPLO (input) CHARACTER*1
! 25: * Specifies whether the details of the factorization are stored
! 26: * as an upper or lower triangular matrix.
! 27: * = 'U': Upper triangular, form is A = U*D*U**T;
! 28: * = 'L': Lower triangular, form is A = L*D*L**T.
! 29: *
! 30: * N (input) INTEGER
! 31: * The order of the matrix A. N >= 0.
! 32: *
! 33: * A (input/output) COMPLEX*16 array, dimension (LDA,N)
! 34: * On entry, the NB diagonal matrix D and the multipliers
! 35: * used to obtain the factor U or L as computed by CSYTRF.
! 36: *
! 37: * On exit, if INFO = 0, the (symmetric) inverse of the original
! 38: * matrix. If UPLO = 'U', the upper triangular part of the
! 39: * inverse is formed and the part of A below the diagonal is not
! 40: * referenced; if UPLO = 'L' the lower triangular part of the
! 41: * inverse is formed and the part of A above the diagonal is
! 42: * not referenced.
! 43: *
! 44: * LDA (input) INTEGER
! 45: * The leading dimension of the array A. LDA >= max(1,N).
! 46: *
! 47: * I1 (input) INTEGER
! 48: * Index of the first row to swap
! 49: *
! 50: * I2 (input) INTEGER
! 51: * Index of the second row to swap
! 52: *
! 53: * =====================================================================
! 54: *
! 55: * ..
! 56: * .. Local Scalars ..
! 57: LOGICAL UPPER
! 58: INTEGER I
! 59: COMPLEX*16 TMP
! 60: *
! 61: * .. External Functions ..
! 62: LOGICAL LSAME
! 63: EXTERNAL LSAME
! 64: * ..
! 65: * .. External Subroutines ..
! 66: EXTERNAL ZSWAP
! 67: * ..
! 68: * .. Executable Statements ..
! 69: *
! 70: UPPER = LSAME( UPLO, 'U' )
! 71: IF (UPPER) THEN
! 72: *
! 73: * UPPER
! 74: * first swap
! 75: * - swap column I1 and I2 from I1 to I1-1
! 76: CALL ZSWAP( I1-1, A(1,I1), 1, A(1,I2), 1 )
! 77: *
! 78: * second swap :
! 79: * - swap A(I1,I1) and A(I2,I2)
! 80: * - swap row I1 from I1+1 to I2-1 with col I2 from I1+1 to I2-1
! 81: * - swap A(I2,I1) and A(I1,I2)
! 82:
! 83: TMP=A(I1,I1)
! 84: A(I1,I1)=A(I2,I2)
! 85: A(I2,I2)=TMP
! 86: *
! 87: DO I=1,I2-I1-1
! 88: TMP=A(I1,I1+I)
! 89: A(I1,I1+I)=DCONJG(A(I1+I,I2))
! 90: A(I1+I,I2)=DCONJG(TMP)
! 91: END DO
! 92: *
! 93: A(I1,I2)=DCONJG(A(I1,I2))
! 94:
! 95: *
! 96: * third swap
! 97: * - swap row I1 and I2 from I2+1 to N
! 98: DO I=I2+1,N
! 99: TMP=A(I1,I)
! 100: A(I1,I)=A(I2,I)
! 101: A(I2,I)=TMP
! 102: END DO
! 103: *
! 104: ELSE
! 105: *
! 106: * LOWER
! 107: * first swap
! 108: * - swap row I1 and I2 from 1 to I1-1
! 109: CALL ZSWAP ( I1-1, A(I1,1), LDA, A(I2,1), LDA )
! 110: *
! 111: * second swap :
! 112: * - swap A(I1,I1) and A(I2,I2)
! 113: * - swap col I1 from I1+1 to I2-1 with row I2 from I1+1 to I2-1
! 114: * - swap A(I2,I1) and A(I1,I2)
! 115:
! 116: TMP=A(I1,I1)
! 117: A(I1,I1)=A(I2,I2)
! 118: A(I2,I2)=TMP
! 119: *
! 120: DO I=1,I2-I1-1
! 121: TMP=A(I1+I,I1)
! 122: A(I1+I,I1)=DCONJG(A(I2,I1+I))
! 123: A(I2,I1+I)=DCONJG(TMP)
! 124: END DO
! 125: *
! 126: A(I2,I1)=DCONJG(A(I2,I1))
! 127: *
! 128: * third swap
! 129: * - swap col I1 and I2 from I2+1 to N
! 130: DO I=I2+1,N
! 131: TMP=A(I,I1)
! 132: A(I,I1)=A(I,I2)
! 133: A(I,I2)=TMP
! 134: END DO
! 135: *
! 136: ENDIF
! 137:
! 138: END SUBROUTINE ZHESWAPR
! 139:
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