double_pendulum_lyap.h

/*------------------------------------------------------------------------------------

2重振り子の方程式のリアプノフスペクトラムの計算

calculating the Lyapunov spectrum of the double pendulum equations

double_pendulum_lyap.h

------------------------------------------------------------------------------------*/

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#define ITERATION 10000000

// #define ITERATION 100000

#define SKIP      100000

#define DELTA_T 0.001 /* step size of the fourth-order Runge-Kutta method */

// parameters

#define G   9.80 // 重力加速度, acceleration of gravity [m/s^2]

#define L1  0.10 // 単振り子1の長さ, length of single pendulum1 [m]

#define L2  0.08 // 単振り子2の長さ, length of single pendulum2 [m]

#define M1  0.20 // おもり1の質量, Mass of weight1 [kg]

#define M2  0.10 // おもり2の質量, Mass of weight2 [kg]

// 初期値

// initial values

#define THETA1  170.0 // 角度, degree

#define THETA2  190.0 // 角度, degree

#define OMEGA1  0.0

#define OMEGA2  0.0

// 変数の数

// number of variables

#define DIM 4

/*------------------------------------------------------*/

extern void solve_double_pendulum_eqs_using_RK4( double v[DIM], double u[DIM][DIM] );

extern void double_pendulum_eqs( double v[DIM], double dfu[DIM][DIM], double dvdt[DIM], double df_k[DIM][DIM] );

extern void gram_schmidt_orth( double u[DIM][DIM], double e[DIM][DIM] );

extern double calc_lyap_dim( double lambda[DIM] );

extern double log2( double x );