libs/CppAddons/CAMath.cpp

   1 // Copyright 2003 "Gilles Degottex"
   2
   3 // This file is part of "CppAddons"
   4
   5 // "CppAddons" is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU Lesser General Public License as published by
   7 // the Free Software Foundation; either version 2.1 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // "CppAddons" is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 // GNU Lesser General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU Lesser General Public License
  16 // along with this program; if not, write to the Free Software
  17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19
  20 #include "CAMath.h"
  21
  22 double Math::SolOfEq2::getPosSol()
  23 {
  24         if(x1<0)
  25         {
  26                 if(x2<0)
  27                 {
  28                         m_err=NE_X1_AND_X2_NEG;
  29                         return 0;
  30                 }
  31                 else            return x2;
  32         }
  33         else
  34         {
  35                 if(x2>0)
  36                 {
  37                         m_err=NE_X1_AND_X2_POS;
  38                         return 0;
  39                 }
  40                 else            return x1;
  41         }
  42 }
  43
  44 Math::SolOfEq2::SolOfEq2(double a, double b, double c)
  45 {
  46         m_err = NE_OK;
  47
  48         if(a==0)
  49         {
  50                 if(b==0)
  51                 {
  52                         m_err=NE_A_AND_B_EQ_ZERO;
  53                         x1=0;
  54                         x2=0;
  55                 }
  56                 else
  57                 {
  58                         x1=-c/b;
  59                         x2=x1;
  60                 }
  61         }
  62         else if(b==0)
  63         {
  64                 double d=-c/a;
  65                 if(d<0)
  66                 {
  67                         m_err=NE_RACINE_NEG;
  68                         x1=0;
  69                         x2=0;
  70                 }
  71                 else
  72                 {
  73                         x1=sqrt(d);
  74                         x2=-x1;
  75                 }
  76         }
  77         else
  78         {
  79                 double d=b*b-4*a*c;
  80                 if(d<0)
  81                 {
  82                         m_err=NE_DISCRIMINENT_NEG;
  83                         x1=0;
  84                         x2=0;
  85                 }
  86                 else
  87                 {
  88                         d=sqrt(d);
  89
  90                         a*=2;
  91                         x1=(-b+d)/a;
  92                         x2=(-b-d)/a;
  93                 }
  94         }
  95 }