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Diffstat (limited to 'chaos/src/driven_anharmonic.hpp')
| -rw-r--r-- | chaos/src/driven_anharmonic.hpp | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/chaos/src/driven_anharmonic.hpp b/chaos/src/driven_anharmonic.hpp new file mode 100644 index 0000000..7d6bfd6 --- /dev/null +++ b/chaos/src/driven_anharmonic.hpp @@ -0,0 +1,102 @@ +// +// +// 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" +#include <cmath> + +// driven anharmonic: +// d2u/dt2 + a * du/dt + b*u + c * u*u*u = k1 + k2*cos(Omega*t) +// equivalent: +// du1/dt = u2 +// du2/dt = -a*u2 - b*u1 -c*u*u*u + k1 + k2*cos(Omega*t) +// taken from Willi-Hans Steeb: Chaos and Fractals + +class driven_anharmonic + : public ode_base<2> +{ +public: + driven_anharmonic() + { + CHAOS_PAR_INIT(method,0); + CHAOS_PAR_INIT(dt,0.01); + + CHAOS_SYS_INIT(u1,0,0); + CHAOS_SYS_INIT(u2,1,1); + + CHAOS_PAR_INIT(a,1); + CHAOS_PAR_INIT(b,-10); + CHAOS_PAR_INIT(c,100); + CHAOS_PAR_INIT(Omega,3.5); + CHAOS_PAR_INIT(k1,0.01); + CHAOS_PAR_INIT(k2,1); + + m_t = 0; + } + + + virtual void m_system(data_t* deriv, data_t* data) + { + data_t u1 = data[0], u2 = data[1]; + + deriv[0] = u2; + deriv[1] = - CHAOS_PARAMETER(a) * u2 - CHAOS_PARAMETER(b) * u1 - + CHAOS_PARAMETER(c) * u1*u1*u1 + CHAOS_PARAMETER(k1) + + CHAOS_PARAMETER(k2) * cos (CHAOS_PARAMETER(Omega) * m_t); + m_t += m_dt; + + if (m_t > 2 * M_PI) + m_t = fmod(m_t, (data_t)(M_PI*2)); + } + + data_t m_t; + + CHAOS_SYSVAR_FUNCS(u1, 0); + CHAOS_SYSVAR_FUNCS(u2, 1); + + CHAOS_SYSPAR_FUNCS(a); + CHAOS_SYSPAR_FUNCS(b); + CHAOS_SYSPAR_FUNCS(c); + CHAOS_SYSPAR_FUNCS(k1); + CHAOS_SYSPAR_FUNCS(k2); + CHAOS_SYSPAR_FUNCS(Omega); +}; + + +#define DRIVEN_ANHARMONIC_CALLBACKS \ +ODE_CALLBACKS; \ +CHAOS_SYS_CALLBACKS(u1); \ +CHAOS_SYS_CALLBACKS(u2); \ +CHAOS_SYS_CALLBACKS(a); \ +CHAOS_SYS_CALLBACKS(b); \ +CHAOS_SYS_CALLBACKS(c); \ +CHAOS_SYS_CALLBACKS(k1); \ +CHAOS_SYS_CALLBACKS(k2); \ +CHAOS_SYS_CALLBACKS(Omega); + +#define DRIVEN_ANHARMONIC_ATTRIBUTES \ +ODE_ATTRIBUTES; \ +CHAOS_SYS_ATTRIBUTE(u1); \ +CHAOS_SYS_ATTRIBUTE(u2); \ +CHAOS_SYS_ATTRIBUTE(a); \ +CHAOS_SYS_ATTRIBUTE(b); \ +CHAOS_SYS_ATTRIBUTE(c); \ +CHAOS_SYS_ATTRIBUTE(k1); \ +CHAOS_SYS_ATTRIBUTE(k2); \ +CHAOS_SYS_ATTRIBUTE(Omega); |