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Mise à jour de lapack vers la version 3.3.0.

    1:       DOUBLE PRECISION FUNCTION ZLANHS( NORM, N, A, LDA, WORK )
    2: *
    3: *  -- LAPACK auxiliary 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          NORM
   10:       INTEGER            LDA, N
   11: *     ..
   12: *     .. Array Arguments ..
   13:       DOUBLE PRECISION   WORK( * )
   14:       COMPLEX*16         A( LDA, * )
   15: *     ..
   16: *
   17: *  Purpose
   18: *  =======
   19: *
   20: *  ZLANHS  returns the value of the one norm,  or the Frobenius norm, or
   21: *  the  infinity norm,  or the  element of  largest absolute value  of a
   22: *  Hessenberg matrix A.
   23: *
   24: *  Description
   25: *  ===========
   26: *
   27: *  ZLANHS returns the value
   28: *
   29: *     ZLANHS = ( max(abs(A(i,j))), NORM = 'M' or 'm'
   30: *              (
   31: *              ( norm1(A),         NORM = '1', 'O' or 'o'
   32: *              (
   33: *              ( normI(A),         NORM = 'I' or 'i'
   34: *              (
   35: *              ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
   36: *
   37: *  where  norm1  denotes the  one norm of a matrix (maximum column sum),
   38: *  normI  denotes the  infinity norm  of a matrix  (maximum row sum) and
   39: *  normF  denotes the  Frobenius norm of a matrix (square root of sum of
   40: *  squares).  Note that  max(abs(A(i,j)))  is not a consistent matrix norm.
   41: *
   42: *  Arguments
   43: *  =========
   44: *
   45: *  NORM    (input) CHARACTER*1
   46: *          Specifies the value to be returned in ZLANHS as described
   47: *          above.
   48: *
   49: *  N       (input) INTEGER
   50: *          The order of the matrix A.  N >= 0.  When N = 0, ZLANHS is
   51: *          set to zero.
   52: *
   53: *  A       (input) COMPLEX*16 array, dimension (LDA,N)
   54: *          The n by n upper Hessenberg matrix A; the part of A below the
   55: *          first sub-diagonal is not referenced.
   56: *
   57: *  LDA     (input) INTEGER
   58: *          The leading dimension of the array A.  LDA >= max(N,1).
   59: *
   60: *  WORK    (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK)),
   61: *          where LWORK >= N when NORM = 'I'; otherwise, WORK is not
   62: *          referenced.
   63: *
   64: * =====================================================================
   65: *
   66: *     .. Parameters ..
   67:       DOUBLE PRECISION   ONE, ZERO
   68:       PARAMETER          ( ONE = 1.0D+0, ZERO = 0.0D+0 )
   69: *     ..
   70: *     .. Local Scalars ..
   71:       INTEGER            I, J
   72:       DOUBLE PRECISION   SCALE, SUM, VALUE
   73: *     ..
   74: *     .. External Functions ..
   75:       LOGICAL            LSAME
   76:       EXTERNAL           LSAME
   77: *     ..
   78: *     .. External Subroutines ..
   79:       EXTERNAL           ZLASSQ
   80: *     ..
   81: *     .. Intrinsic Functions ..
   82:       INTRINSIC          ABS, MAX, MIN, SQRT
   83: *     ..
   84: *     .. Executable Statements ..
   85: *
   86:       IF( N.EQ.0 ) THEN
   87:          VALUE = ZERO
   88:       ELSE IF( LSAME( NORM, 'M' ) ) THEN
   89: *
   90: *        Find max(abs(A(i,j))).
   91: *
   92:          VALUE = ZERO
   93:          DO 20 J = 1, N
   94:             DO 10 I = 1, MIN( N, J+1 )
   95:                VALUE = MAX( VALUE, ABS( A( I, J ) ) )
   96:    10       CONTINUE
   97:    20    CONTINUE
   98:       ELSE IF( ( LSAME( NORM, 'O' ) ) .OR. ( NORM.EQ.'1' ) ) THEN
   99: *
  100: *        Find norm1(A).
  101: *
  102:          VALUE = ZERO
  103:          DO 40 J = 1, N
  104:             SUM = ZERO
  105:             DO 30 I = 1, MIN( N, J+1 )
  106:                SUM = SUM + ABS( A( I, J ) )
  107:    30       CONTINUE
  108:             VALUE = MAX( VALUE, SUM )
  109:    40    CONTINUE
  110:       ELSE IF( LSAME( NORM, 'I' ) ) THEN
  111: *
  112: *        Find normI(A).
  113: *
  114:          DO 50 I = 1, N
  115:             WORK( I ) = ZERO
  116:    50    CONTINUE
  117:          DO 70 J = 1, N
  118:             DO 60 I = 1, MIN( N, J+1 )
  119:                WORK( I ) = WORK( I ) + ABS( A( I, J ) )
  120:    60       CONTINUE
  121:    70    CONTINUE
  122:          VALUE = ZERO
  123:          DO 80 I = 1, N
  124:             VALUE = MAX( VALUE, WORK( I ) )
  125:    80    CONTINUE
  126:       ELSE IF( ( LSAME( NORM, 'F' ) ) .OR. ( LSAME( NORM, 'E' ) ) ) THEN
  127: *
  128: *        Find normF(A).
  129: *
  130:          SCALE = ZERO
  131:          SUM = ONE
  132:          DO 90 J = 1, N
  133:             CALL ZLASSQ( MIN( N, J+1 ), A( 1, J ), 1, SCALE, SUM )
  134:    90    CONTINUE
  135:          VALUE = SCALE*SQRT( SUM )
  136:       END IF
  137: *
  138:       ZLANHS = VALUE
  139:       RETURN
  140: *
  141: *     End of ZLANHS
  142: *
  143:       END