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template_lapack_lapy3.h
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/* Ergo, version 3.2, a program for linear scaling electronic structure
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* calculations.
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* Copyright (C) 2012 Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Primary academic reference:
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* KohnâSham Density Functional Theory Electronic Structure Calculations
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* with Linearly Scaling Computational Time and Memory Usage,
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* Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek,
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* J. Chem. Theory Comput. 7, 340 (2011),
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* <http://dx.doi.org/10.1021/ct100611z>
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*
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* For further information about Ergo, see <http://www.ergoscf.org>.
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*/
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/* This file belongs to the template_lapack part of the Ergo source
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* code. The source files in the template_lapack directory are modified
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* versions of files originally distributed as CLAPACK, see the
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* Copyright/license notice in the file template_lapack/COPYING.
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*/
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#ifndef TEMPLATE_LAPACK_LAPY3_HEADER
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#define TEMPLATE_LAPACK_LAPY3_HEADER
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template
<
class
Treal>
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Treal
template_lapack_lapy3
(Treal *x, Treal *y, Treal *z__)
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{
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/* -- LAPACK auxiliary routine (version 3.0) --
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Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
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Courant Institute, Argonne National Lab, and Rice University
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October 31, 1992
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Purpose
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=======
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DLAPY3 returns sqrt(x**2+y**2+z**2), taking care not to cause
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unnecessary overflow.
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Arguments
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=========
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X (input) DOUBLE PRECISION
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Y (input) DOUBLE PRECISION
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Z (input) DOUBLE PRECISION
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X, Y and Z specify the values x, y and z.
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===================================================================== */
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/* System generated locals */
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Treal ret_val, d__1, d__2, d__3;
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/* Local variables */
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Treal xabs, yabs, zabs, w;
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xabs =
absMACRO
(*x);
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yabs =
absMACRO
(*y);
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zabs =
absMACRO
(*z__);
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/* Computing MAX */
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d__1 =
maxMACRO
(xabs,yabs);
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w =
maxMACRO
(d__1,zabs);
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if
(w == 0.) {
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ret_val = 0.;
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}
else
{
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/* Computing 2nd power */
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d__1 = xabs / w;
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/* Computing 2nd power */
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d__2 = yabs / w;
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/* Computing 2nd power */
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d__3 = zabs / w;
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ret_val = w *
template_blas_sqrt
(d__1 * d__1 + d__2 * d__2 + d__3 * d__3);
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}
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return
ret_val;
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/* End of DLAPY3 */
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}
/* dlapy3_ */
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#endif
source
matrix
template_lapack
lapack
template_lapack_lapy3.h
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