Return to dtpttr.f CVS log

Up to [local] / rpl / lapack / lapack

Première mise à jour de lapack et blas.

    1: *> \brief \b DTPTTR copies a triangular matrix from the standard packed format (TP) to the standard full format (TR).
    2: *
    3: *  =========== DOCUMENTATION ===========
    4: *
    5: * Online html documentation available at
    6: *            http://www.netlib.org/lapack/explore-html/
    7: *
    8: *> \htmlonly
    9: *> Download DTPTTR + dependencies
   10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dtpttr.f">
   11: *> [TGZ]</a>
   12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dtpttr.f">
   13: *> [ZIP]</a>
   14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dtpttr.f">
   15: *> [TXT]</a>
   16: *> \endhtmlonly
   17: *
   18: *  Definition:
   19: *  ===========
   20: *
   21: *       SUBROUTINE DTPTTR( UPLO, N, AP, A, LDA, INFO )
   22: *
   23: *       .. Scalar Arguments ..
   24: *       CHARACTER          UPLO
   25: *       INTEGER            INFO, N, LDA
   26: *       ..
   27: *       .. Array Arguments ..
   28: *       DOUBLE PRECISION   A( LDA, * ), AP( * )
   29: *       ..
   30: *
   31: *
   32: *> \par Purpose:
   33: *  =============
   34: *>
   35: *> \verbatim
   36: *>
   37: *> DTPTTR copies a triangular matrix A from standard packed format (TP)
   38: *> to standard full format (TR).
   39: *> \endverbatim
   40: *
   41: *  Arguments:
   42: *  ==========
   43: *
   44: *> \param[in] UPLO
   45: *> \verbatim
   46: *>          UPLO is CHARACTER*1
   47: *>          = 'U':  A is upper triangular.
   48: *>          = 'L':  A is lower triangular.
   49: *> \endverbatim
   50: *>
   51: *> \param[in] N
   52: *> \verbatim
   53: *>          N is INTEGER
   54: *>          The order of the matrix A. N >= 0.
   55: *> \endverbatim
   56: *>
   57: *> \param[in] AP
   58: *> \verbatim
   59: *>          AP is DOUBLE PRECISION array, dimension ( N*(N+1)/2 ),
   60: *>          On entry, the upper or lower triangular matrix A, packed
   61: *>          columnwise in a linear array. The j-th column of A is stored
   62: *>          in the array AP as follows:
   63: *>          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
   64: *>          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
   65: *> \endverbatim
   66: *>
   67: *> \param[out] A
   68: *> \verbatim
   69: *>          A is DOUBLE PRECISION array, dimension ( LDA, N )
   70: *>          On exit, the triangular matrix A.  If UPLO = 'U', the leading
   71: *>          N-by-N upper triangular part of A contains the upper
   72: *>          triangular part of the matrix A, and the strictly lower
   73: *>          triangular part of A is not referenced.  If UPLO = 'L', the
   74: *>          leading N-by-N lower triangular part of A contains the lower
   75: *>          triangular part of the matrix A, and the strictly upper
   76: *>          triangular part of A is not referenced.
   77: *> \endverbatim
   78: *>
   79: *> \param[in] LDA
   80: *> \verbatim
   81: *>          LDA is INTEGER
   82: *>          The leading dimension of the array A.  LDA >= max(1,N).
   83: *> \endverbatim
   84: *>
   85: *> \param[out] INFO
   86: *> \verbatim
   87: *>          INFO is INTEGER
   88: *>          = 0:  successful exit
   89: *>          < 0:  if INFO = -i, the i-th argument had an illegal value
   90: *> \endverbatim
   91: *
   92: *  Authors:
   93: *  ========
   94: *
   95: *> \author Univ. of Tennessee
   96: *> \author Univ. of California Berkeley
   97: *> \author Univ. of Colorado Denver
   98: *> \author NAG Ltd.
   99: *
  100: *> \ingroup doubleOTHERcomputational
  101: *
  102: *  =====================================================================
  103:       SUBROUTINE DTPTTR( UPLO, N, AP, A, LDA, INFO )
  104: *
  105: *  -- LAPACK computational routine --
  106: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
  107: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
  108: *
  109: *     .. Scalar Arguments ..
  110:       CHARACTER          UPLO
  111:       INTEGER            INFO, N, LDA
  112: *     ..
  113: *     .. Array Arguments ..
  114:       DOUBLE PRECISION   A( LDA, * ), AP( * )
  115: *     ..
  116: *
  117: *  =====================================================================
  118: *
  119: *     .. Parameters ..
  120: *     ..
  121: *     .. Local Scalars ..
  122:       LOGICAL            LOWER
  123:       INTEGER            I, J, K
  124: *     ..
  125: *     .. External Functions ..
  126:       LOGICAL            LSAME
  127:       EXTERNAL           LSAME
  128: *     ..
  129: *     .. External Subroutines ..
  130:       EXTERNAL           XERBLA
  131: *     ..
  132: *     .. Executable Statements ..
  133: *
  134: *     Test the input parameters.
  135: *
  136:       INFO = 0
  137:       LOWER = LSAME( UPLO, 'L' )
  138:       IF( .NOT.LOWER .AND. .NOT.LSAME( UPLO, 'U' ) ) THEN
  139:          INFO = -1
  140:       ELSE IF( N.LT.0 ) THEN
  141:          INFO = -2
  142:       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
  143:          INFO = -5
  144:       END IF
  145:       IF( INFO.NE.0 ) THEN
  146:          CALL XERBLA( 'DTPTTR', -INFO )
  147:          RETURN
  148:       END IF
  149: *
  150:       IF( LOWER ) THEN
  151:          K = 0
  152:          DO J = 1, N
  153:             DO I = J, N
  154:                K = K + 1
  155:                A( I, J ) = AP( K )
  156:             END DO
  157:          END DO
  158:       ELSE
  159:          K = 0
  160:          DO J = 1, N
  161:             DO I = 1, J
  162:                K = K + 1
  163:                A( I, J ) = AP( K )
  164:             END DO
  165:          END DO
  166:       END IF
  167: *
  168: *
  169:       RETURN
  170: *
  171: *     End of DTPTTR
  172: *
  173:       END