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Mise à jour de lapack vers la version 3.3.0.

    1:       SUBROUTINE ZUPGTR( UPLO, N, AP, TAU, Q, LDQ, WORK, INFO )
    2: *
    3: *  -- LAPACK routine (version 3.2) --
    4: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
    5: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
    6: *     November 2006
    7: *
    8: *     .. Scalar Arguments ..
    9:       CHARACTER          UPLO
   10:       INTEGER            INFO, LDQ, N
   11: *     ..
   12: *     .. Array Arguments ..
   13:       COMPLEX*16         AP( * ), Q( LDQ, * ), TAU( * ), WORK( * )
   14: *     ..
   15: *
   16: *  Purpose
   17: *  =======
   18: *
   19: *  ZUPGTR generates a complex unitary matrix Q which is defined as the
   20: *  product of n-1 elementary reflectors H(i) of order n, as returned by
   21: *  ZHPTRD using packed storage:
   22: *
   23: *  if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),
   24: *
   25: *  if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).
   26: *
   27: *  Arguments
   28: *  =========
   29: *
   30: *  UPLO    (input) CHARACTER*1
   31: *          = 'U': Upper triangular packed storage used in previous
   32: *                 call to ZHPTRD;
   33: *          = 'L': Lower triangular packed storage used in previous
   34: *                 call to ZHPTRD.
   35: *
   36: *  N       (input) INTEGER
   37: *          The order of the matrix Q. N >= 0.
   38: *
   39: *  AP      (input) COMPLEX*16 array, dimension (N*(N+1)/2)
   40: *          The vectors which define the elementary reflectors, as
   41: *          returned by ZHPTRD.
   42: *
   43: *  TAU     (input) COMPLEX*16 array, dimension (N-1)
   44: *          TAU(i) must contain the scalar factor of the elementary
   45: *          reflector H(i), as returned by ZHPTRD.
   46: *
   47: *  Q       (output) COMPLEX*16 array, dimension (LDQ,N)
   48: *          The N-by-N unitary matrix Q.
   49: *
   50: *  LDQ     (input) INTEGER
   51: *          The leading dimension of the array Q. LDQ >= max(1,N).
   52: *
   53: *  WORK    (workspace) COMPLEX*16 array, dimension (N-1)
   54: *
   55: *  INFO    (output) INTEGER
   56: *          = 0:  successful exit
   57: *          < 0:  if INFO = -i, the i-th argument had an illegal value
   58: *
   59: *  =====================================================================
   60: *
   61: *     .. Parameters ..
   62:       COMPLEX*16         CZERO, CONE
   63:       PARAMETER          ( CZERO = ( 0.0D+0, 0.0D+0 ),
   64:      $                   CONE = ( 1.0D+0, 0.0D+0 ) )
   65: *     ..
   66: *     .. Local Scalars ..
   67:       LOGICAL            UPPER
   68:       INTEGER            I, IINFO, IJ, J
   69: *     ..
   70: *     .. External Functions ..
   71:       LOGICAL            LSAME
   72:       EXTERNAL           LSAME
   73: *     ..
   74: *     .. External Subroutines ..
   75:       EXTERNAL           XERBLA, ZUNG2L, ZUNG2R
   76: *     ..
   77: *     .. Intrinsic Functions ..
   78:       INTRINSIC          MAX
   79: *     ..
   80: *     .. Executable Statements ..
   81: *
   82: *     Test the input arguments
   83: *
   84:       INFO = 0
   85:       UPPER = LSAME( UPLO, 'U' )
   86:       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
   87:          INFO = -1
   88:       ELSE IF( N.LT.0 ) THEN
   89:          INFO = -2
   90:       ELSE IF( LDQ.LT.MAX( 1, N ) ) THEN
   91:          INFO = -6
   92:       END IF
   93:       IF( INFO.NE.0 ) THEN
   94:          CALL XERBLA( 'ZUPGTR', -INFO )
   95:          RETURN
   96:       END IF
   97: *
   98: *     Quick return if possible
   99: *
  100:       IF( N.EQ.0 )
  101:      $   RETURN
  102: *
  103:       IF( UPPER ) THEN
  104: *
  105: *        Q was determined by a call to ZHPTRD with UPLO = 'U'
  106: *
  107: *        Unpack the vectors which define the elementary reflectors and
  108: *        set the last row and column of Q equal to those of the unit
  109: *        matrix
  110: *
  111:          IJ = 2
  112:          DO 20 J = 1, N - 1
  113:             DO 10 I = 1, J - 1
  114:                Q( I, J ) = AP( IJ )
  115:                IJ = IJ + 1
  116:    10       CONTINUE
  117:             IJ = IJ + 2
  118:             Q( N, J ) = CZERO
  119:    20    CONTINUE
  120:          DO 30 I = 1, N - 1
  121:             Q( I, N ) = CZERO
  122:    30    CONTINUE
  123:          Q( N, N ) = CONE
  124: *
  125: *        Generate Q(1:n-1,1:n-1)
  126: *
  127:          CALL ZUNG2L( N-1, N-1, N-1, Q, LDQ, TAU, WORK, IINFO )
  128: *
  129:       ELSE
  130: *
  131: *        Q was determined by a call to ZHPTRD with UPLO = 'L'.
  132: *
  133: *        Unpack the vectors which define the elementary reflectors and
  134: *        set the first row and column of Q equal to those of the unit
  135: *        matrix
  136: *
  137:          Q( 1, 1 ) = CONE
  138:          DO 40 I = 2, N
  139:             Q( I, 1 ) = CZERO
  140:    40    CONTINUE
  141:          IJ = 3
  142:          DO 60 J = 2, N
  143:             Q( 1, J ) = CZERO
  144:             DO 50 I = J + 1, N
  145:                Q( I, J ) = AP( IJ )
  146:                IJ = IJ + 1
  147:    50       CONTINUE
  148:             IJ = IJ + 2
  149:    60    CONTINUE
  150:          IF( N.GT.1 ) THEN
  151: *
  152: *           Generate Q(2:n,2:n)
  153: *
  154:             CALL ZUNG2R( N-1, N-1, N-1, Q( 2, 2 ), LDQ, TAU, WORK,
  155:      $                   IINFO )
  156:          END IF
  157:       END IF
  158:       RETURN
  159: *
  160: *     End of ZUPGTR
  161: *
  162:       END