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//
//
// chaos~
// Copyright (C) 2004 Tim Blechmann
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING. If not, write to
// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.
#include "ode_base.hpp"
// lorenz model: dx1/dt = sigma * (x2 - x1)
// dx2/dt = - x1 * x3 + r * x1 - x2
// dx3/dt = x1 * x2 - b * x3
// taken from Willi-Hans Steeb: Chaos and Fractals
class lorenz
: public ode_base
{
public:
lorenz():
ode_base(3)
{
CHAOS_PAR_INIT(method,0);
CHAOS_PAR_INIT(dt,0.01);
CHAOS_SYS_INIT(x1,0.8,0);
CHAOS_SYS_INIT(x2,0.7,1);
CHAOS_SYS_INIT(x3,0.6,2);
CHAOS_PAR_INIT(sigma,16);
CHAOS_PAR_INIT(b,4);
CHAOS_PAR_INIT(r,40);
}
~lorenz()
{
}
virtual void m_system(data_t* deriv, data_t* data)
{
data_t x1 = data[0], x2 = data[1], x3 = data[2];
deriv[0] = CHAOS_PARAMETER(sigma) * (x2 - x1);
deriv[1] = - x1 * x3 + CHAOS_PARAMETER(r) * x1 - x2;
deriv[2] = x1 * x2 - CHAOS_PARAMETER(b) * x3;
}
/* function has a fix point for x1 == x2 == x3 == 0 */
virtual void m_verify()
{
if (m_data[0] == 0 && m_data[1] == 0 && m_data[2] == 0)
for (int i = 0; i != 3; ++i)
m_data[i] = rand_range(0,3);
}
CHAOS_SYSVAR_FUNCS(x1, 0);
CHAOS_SYSVAR_FUNCS(x2, 1);
CHAOS_SYSVAR_FUNCS(x3, 2);
CHAOS_SYSPAR_FUNCS_PRED(sigma, m_pred);
CHAOS_SYSPAR_FUNCS_PRED(b, m_pred);
CHAOS_SYSPAR_FUNCS_PRED(r, m_pred);
bool m_pred (t_float f)
{
return (f > 0);
}
};
#define LORENZ_CALLBACKS \
ODE_CALLBACKS; \
CHAOS_SYS_CALLBACKS(x1); \
CHAOS_SYS_CALLBACKS(x2); \
CHAOS_SYS_CALLBACKS(x3); \
CHAOS_SYS_CALLBACKS(sigma); \
CHAOS_SYS_CALLBACKS(r); \
CHAOS_SYS_CALLBACKS(b);
#define LORENZ_ATTRIBUTES \
ODE_ATTRIBUTES; \
CHAOS_SYS_ATTRIBUTE(x1); \
CHAOS_SYS_ATTRIBUTE(x2); \
CHAOS_SYS_ATTRIBUTE(x3); \
CHAOS_SYS_ATTRIBUTE(sigma); \
CHAOS_SYS_ATTRIBUTE(r); \
CHAOS_SYS_ATTRIBUTE(b);
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