test/src/TestZeroFinder.cpp

   1 /* Copyright_License {
   2
   3   XCSoar Glide Computer - http://www.xcsoar.org/
   4   Copyright (C) 2000-2013 The XCSoar Project
   5   A detailed list of copyright holders can be found in the file "AUTHORS".
   6
   7   This program is free software; you can redistribute it and/or
   8   modify it under the terms of the GNU General Public License
   9   as published by the Free Software Foundation; either version 2
  10   of the License, or (at your option) any later version.
  11
  12   This program is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15   GNU General Public License for more details.
  16
  17   You should have received a copy of the GNU General Public License
  18   along with this program; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20 }
  21 */
  22
  23 #include "Math/ZeroFinder.hpp"
  24 #include "TestUtil.hpp"
  25
  26 class ZeroFinderTest: public ZeroFinder
  27 {
  28   unsigned func;
  29
  30 public:
  31   ZeroFinderTest(fixed x_min, fixed x_max, unsigned _func = 0) :
  32     ZeroFinder(x_min, x_max, fixed(0.0001)), func(_func) {}
  33
  34   fixed f(const fixed x);
  35 };
  36
  37 fixed
  38 ZeroFinderTest::f(const fixed x)
  39 {
  40   if (func == 0)
  41     return fixed(2) * x * x - fixed(3) * x - fixed(5);
  42
  43   if (func == 1)
  44     return pow(fixed(2), x) - fixed(3);
  45
  46   if (func == 2)
  47     return cos(x);
  48
  49   gcc_unreachable();
  50   assert(false);
  51   return fixed(0);
  52 }
  53
  54 int main(int argc, char **argv)
  55 {
  56   plan_tests(18);
  57
  58   ZeroFinderTest zf(fixed(-100), fixed(100), 0);
  59   ok1(equals(zf.find_zero(fixed(-150)), fixed(-1)));
  60   ok1(equals(zf.find_zero(fixed(0)), fixed(-1)));
  61   // ok1(equals(zf.find_zero(fixed(140)), fixed(2.5))); ???
  62   ok1(equals(zf.find_zero(fixed(140)), fixed(-1)));
  63
  64   ok1(equals(zf.find_min(fixed(-150)), fixed(0.75)));
  65   ok1(equals(zf.find_min(fixed(0)), fixed(0.75)));
  66   ok1(equals(zf.find_min(fixed(150)), fixed(0.75)));
  67
  68   ZeroFinderTest zf2(fixed(0), fixed(100), 0);
  69   ok1(equals(zf2.find_zero(fixed(-150)), fixed(2.5)));
  70   ok1(equals(zf2.find_zero(fixed(0)), fixed(2.5)));
  71   ok1(equals(zf2.find_zero(fixed(140)), fixed(2.5)));
  72
  73   ZeroFinderTest zf3(fixed(0), fixed(10), 1);
  74   ok1(equals(zf3.find_zero(fixed(-150)), fixed(1.584963)));
  75   ok1(equals(zf3.find_zero(fixed(1)), fixed(1.584963)));
  76   ok1(equals(zf3.find_zero(fixed(140)), fixed(1.584963)));
  77
  78   ZeroFinderTest zf4(fixed(0), fixed_pi + fixed(1), 2);
  79   ok1(equals(zf4.find_zero(fixed(-150)), fixed_half_pi));
  80   ok1(equals(zf4.find_zero(fixed(1)), fixed_half_pi));
  81   ok1(equals(zf4.find_zero(fixed(140)), fixed_half_pi));
  82
  83   ok1(equals(zf4.find_min(fixed(-150)), fixed_pi));
  84   ok1(equals(zf4.find_min(fixed(1)), fixed_pi));
  85   ok1(equals(zf4.find_min(fixed(140)), fixed_pi));
  86
  87   return exit_status();
  88 }