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<center><a href="slepcmath.h">Actual source code: slepcmath.h</a></center><br>
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<div id="version" align=right><b>slepc-3.7.3 2016-09-29</b></div>
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<pre width="80"><a name="line1"> 1: </a><font color="#B22222">/*</font>
<a name="line2"> 2: </a><font color="#B22222"> SLEPc mathematics include file. Defines basic operations and functions.</font>
<a name="line3"> 3: </a><font color="#B22222"> This file is included by slepcsys.h and should not be used directly.</font>
<a name="line5"> 5: </a><font color="#B22222"> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -</font>
<a name="line6"> 6: </a><font color="#B22222"> SLEPc - Scalable Library for Eigenvalue Problem Computations</font>
<a name="line7"> 7: </a><font color="#B22222"> Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain</font>
<a name="line9"> 9: </a><font color="#B22222"> This file is part of SLEPc.</font>
<a name="line11"> 11: </a><font color="#B22222"> SLEPc is free software: you can redistribute it and/or modify it under the</font>
<a name="line12"> 12: </a><font color="#B22222"> terms of version 3 of the GNU Lesser General Public License as published by</font>
<a name="line13"> 13: </a><font color="#B22222"> the Free Software Foundation.</font>
<a name="line15"> 15: </a><font color="#B22222"> SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY</font>
<a name="line16"> 16: </a><font color="#B22222"> WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS</font>
<a name="line17"> 17: </a><font color="#B22222"> FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for</font>
<a name="line18"> 18: </a><font color="#B22222"> more details.</font>
<a name="line20"> 20: </a><font color="#B22222"> You should have received a copy of the GNU Lesser General Public License</font>
<a name="line21"> 21: </a><font color="#B22222"> along with SLEPc. If not, see <http://www.gnu.org/licenses/>.</font>
<a name="line22"> 22: </a><font color="#B22222"> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -</font>
<a name="line23"> 23: </a><font color="#B22222">*/</font>
<a name="line28"> 28: </a><font color="#B22222">/*</font>
<a name="line29"> 29: </a><font color="#B22222"> Default tolerance for the different solvers, depending on the precision</font>
<a name="line30"> 30: </a><font color="#B22222">*/</font>
<a name="line31"> 31: </a><font color="#A020F0">#if defined(PETSC_USE_REAL_SINGLE)</font>
<a name="line32"> 32: </a><font color="#A020F0"># define SLEPC_DEFAULT_TOL 1e-6</font>
<a name="line33"> 33: </a><font color="#A020F0">#elif defined(PETSC_USE_REAL_DOUBLE)</font>
<a name="line34"> 34: </a><font color="#A020F0"># define SLEPC_DEFAULT_TOL 1e-8</font>
<a name="line35"> 35: </a><font color="#A020F0">#elif defined(PETSC_USE_REAL___FLOAT128)</font>
<a name="line36"> 36: </a><font color="#A020F0"># define SLEPC_DEFAULT_TOL 1e-16</font>
<a name="line37"> 37: </a><font color="#A020F0">#else</font>
<a name="line38"> 38: </a><font color="#A020F0"># define SLEPC_DEFAULT_TOL 1e-7</font>
<a name="line39"> 39: </a><font color="#A020F0">#endif</font>
<a name="line41"> 41: </a><font color="#B22222">/*@C</font>
<a name="line42"> 42: </a><font color="#B22222"> SlepcAbs - Returns sqrt(x**2+y**2), taking care not to cause unnecessary</font>
<a name="line43"> 43: </a><font color="#B22222"> overflow. It is based on LAPACK's DLAPY2.</font>
<a name="line45"> 45: </a><font color="#B22222"> Not Collective</font>
<a name="line47"> 47: </a><font color="#B22222"> Input parameters:</font>
<a name="line48"> 48: </a><font color="#B22222">. x,y - the real numbers</font>
<a name="line50"> 50: </a><font color="#B22222"> Output parameter:</font>
<a name="line51"> 51: </a><font color="#B22222">. return - the result</font>
<a name="line53"> 53: </a><font color="#B22222"> Note:</font>
<a name="line54"> 54: </a><font color="#B22222"> This function is not available from Fortran.</font>
<a name="line56"> 56: </a><font color="#B22222"> Level: developer</font>
<a name="line57"> 57: </a><font color="#B22222">@*/</font>
<a name="line58"> 58: </a><strong><font color="#4169E1"><a name="SlepcAbs"></a>PETSC_STATIC_INLINE PetscReal SlepcAbs(PetscReal x,PetscReal y)</font></strong>
<a name="line59"> 59: </a>{
<a name="line60"> 60: </a> PetscReal w,z,t,xabs=PetscAbs(x),yabs=PetscAbs(y);
<a name="line62"> 62: </a> w = PetscMax(xabs,yabs);
<a name="line63"> 63: </a> z = PetscMin(xabs,yabs);
<a name="line64"> 64: </a> <font color="#4169E1">if</font> (z == 0.0) <font color="#4169E1">return</font> w;
<a name="line65"> 65: </a> t = z/w;
<a name="line66"> 66: </a> <font color="#4169E1">return</font> w*PetscSqrtReal(1.0+t*t);
<a name="line67"> 67: </a>}
<a name="line69"> 69: </a><font color="#B22222">/*MC</font>
<a name="line70"> 70: </a><font color="#B22222"> SlepcAbsEigenvalue - Returns the absolute value of a complex number given</font>
<a name="line71"> 71: </a><font color="#B22222"> its real and imaginary parts.</font>
<a name="line73"> 73: </a><font color="#B22222"> Synopsis:</font>
<a name="line74"> 74: </a><font color="#B22222"> PetscReal SlepcAbsEigenvalue(PetscScalar x,PetscScalar y)</font>
<a name="line76"> 76: </a><font color="#B22222"> Not Collective</font>
<a name="line78"> 78: </a><font color="#B22222"> Input parameters:</font>
<a name="line79"> 79: </a><font color="#B22222">+ x - the real part of the complex number</font>
<a name="line80"> 80: </a><font color="#B22222">- y - the imaginary part of the complex number</font>
<a name="line82"> 82: </a><font color="#B22222"> Notes:</font>
<a name="line83"> 83: </a><font color="#B22222"> This function computes sqrt(x**2+y**2), taking care not to cause unnecessary</font>
<a name="line84"> 84: </a><font color="#B22222"> overflow. It is based on LAPACK's DLAPY2.</font>
<a name="line86"> 86: </a><font color="#B22222"> This function is not available from Fortran.</font>
<a name="line88"> 88: </a><font color="#B22222"> Level: developer</font>
<a name="line89"> 89: </a><font color="#B22222">M*/</font>
<a name="line90"> 90: </a><font color="#A020F0">#if !defined(PETSC_USE_COMPLEX)</font>
<a name="line91"> 91: </a><strong><font color="#228B22">#define SlepcAbsEigenvalue(x,y) SlepcAbs(x,y)</font></strong>
<a name="line92"> 92: </a><font color="#A020F0">#else</font>
<a name="line93"> 93: </a><strong><font color="#228B22">#define SlepcAbsEigenvalue(x,y) PetscAbsScalar(x)</font></strong>
<a name="line94"> 94: </a><font color="#A020F0">#endif</font>
<a name="line96"> 96: </a><font color="#A020F0">#endif</font>
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