dcabs1.f

来自「基于Blas CLapck的.用过的人知道是干啥的」· F 代码 · 共 86 行

      DOUBLE PRECISION FUNCTION DCABS1( Z )
*
*  -- Automatically Tuned Linear Algebra Software (ATLAS)
*     (C) Copyright 2000 All Rights Reserved
*
*  -- ATLAS routine -- F77 Interface -- Version 3.2 -- December 25, 2000
*
*  Author         : Antoine P. Petitet
*  Originally developed at the University of Tennessee,
*  Innovative Computing Laboratory,  Knoxville TN, 37996-1301, USA.
*
*  ---------------------------------------------------------------------
*
*  -- Copyright notice and Licensing terms:
*
*  Redistribution  and  use in  source and binary forms, with or without
*  modification, are  permitted provided  that the following  conditions
*  are met:
*
*  1. Redistributions  of  source  code  must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*  2. Redistributions in binary form must reproduce  the above copyright
*     notice,  this list of conditions, and the  following disclaimer in
*     the documentation and/or other materials provided with the distri-
*     bution.
*  3. The name of the University,  the ATLAS group,  or the names of its
*     contributors  may not be used to endorse or promote products deri-
*     ved from this software without specific written permission.
*
*  -- Disclaimer:
*
*  THIS  SOFTWARE  IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
*  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,  INCLUDING,  BUT NOT
*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
*  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY
*  OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,  INDIRECT, INCIDENTAL, SPE-
*  CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
*  TO,  PROCUREMENT  OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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*  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*  ---------------------------------------------------------------------
*
*     .. Scalar Arguments ..
      DOUBLE COMPLEX     Z
*     ..
*
*  Purpose
*  =======
*
*  DCABS1 returns |real( z )| + |imag( z )|  where z is a double complex
*  number.
*
*  Arguments
*  =========
*
*  Z       (input)                       COMPLEX*16
*          On entry, the complex number z.
*
*  =====================================================================
*
*     .. Local Scalars ..
      DOUBLE COMPLEX     ZZ
*     ..
*     .. Local Arrays ..
      DOUBLE PRECISION   T( 2 )
*     ..
*     .. Equivalence Statements ..
      EQUIVALENCE        ( ZZ, T( 1 ) )
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          DABS
*     ..
*     .. Executable Statements ..
*
      ZZ = Z
      DCABS1 = DABS( T( 1 ) ) + DABS( T( 2 ) )
*
      RETURN
*
*     End of DCABS1
*
      END