diff options
Diffstat (limited to 'chaos/src/chua.hpp')
| -rw-r--r-- | chaos/src/chua.hpp | 83 |
1 files changed, 74 insertions, 9 deletions
diff --git a/chaos/src/chua.hpp b/chaos/src/chua.hpp index e54df47..3d44708 100644 --- a/chaos/src/chua.hpp +++ b/chaos/src/chua.hpp @@ -28,7 +28,7 @@ // a*x (for -1 <= x <= 1 // b*x - a + b (for x < -1) // -// taken from Viktor Avrutin: lecture note +// taken from Viktor Avrutin: lecture notes class chua: public ode_base @@ -38,14 +38,17 @@ public: { CHAOS_PRECONSTRUCTOR; - CHAOS_SYS_INIT(x1,1,0); + CHAOS_PAR_INIT(method,2); + CHAOS_PAR_INIT(dt,0.05); + + CHAOS_SYS_INIT(x1,1,1); CHAOS_SYS_INIT(x2,1,1); - CHAOS_SYS_INIT(x3,1,2); + CHAOS_SYS_INIT(x3,1,1); - CHAOS_PAR_INIT(a,1.4); - CHAOS_PAR_INIT(b,0.3); - CHAOS_PAR_INIT(alpha,0.3); - CHAOS_PAR_INIT(beta,0.3); + CHAOS_PAR_INIT(a,140); + CHAOS_PAR_INIT(b,30); + CHAOS_PAR_INIT(alpha,30); + CHAOS_PAR_INIT(beta,30); CHAOS_POSTCONSTRUCTOR; @@ -79,12 +82,74 @@ public: deriv[2] = - CHAOS_PARAMETER(beta) * x2; } + virtual void m_verify() + { + data_t x1 = m_data[0]; + data_t x2 = m_data[1]; + data_t x3 = m_data[2]; + + if ( CHAOS_ABS(x3) < 1e-10) + x3 = 0; + + if (x1 == 0 && x2 == 0 && x3 == 0) /* fixpoint at (0,0,0) */ + { + reset(); + return; + } + else + { + data_t c = m_c; + if (m_c) + { + data_t mc = - c; + if (x1 == c && x3 == mc) /* fixpoint at (c,0,-c) */ + { + reset(); + return; + } + if (x1 == mc && x3 == c) /* fixpoint at (-c,0,c) */ + { + reset(); + return; + } + } + } + } + + inline void reset() + { + m_data[0] = rand_range(-1,1); + m_data[1] = rand_range(-1,1); + m_data[2] = rand_range(-1,1); + } + CHAOS_SYSVAR_FUNCS(x1, 0); CHAOS_SYSVAR_FUNCS(x2, 1); CHAOS_SYSVAR_FUNCS(x3, 2); - CHAOS_SYSPAR_FUNCS(a); - CHAOS_SYSPAR_FUNCS(b); + /* due to stability issues, we hook into the predicates */ + data_t m_c; + bool m_pred_a(data_t a) + { + data_t b = CHAOS_PARAMETER(b); + m_c = (b - a) / (b + 1); + return true; + } + + bool m_pred_b(data_t b) + { + if (b == -1) + m_c = 0; + else + { + data_t a = CHAOS_PARAMETER(a); + m_c = (b - a) / (b + 1); + } + return true; + } + + CHAOS_SYSPAR_FUNCS_PRED(a, m_pred_a); + CHAOS_SYSPAR_FUNCS_PRED(b, m_pred_b); CHAOS_SYSPAR_FUNCS(alpha); CHAOS_SYSPAR_FUNCS(beta); }; |