English: Strange attractor, aka Japanese attractor or Ueda attractor, obtained from the forced Duffing equation
with the parameters (k = 0.1, B = 12.0) and the initial condition (x = 3.0, y = 0.1). The plots were made by Runge–Kutta method (Scilab ODE solver) with time step 2π.
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Scilab source
This media was created with Scilab, a free open-source software.
Here is a listing of the Scilab source used to create this file.
clear;//Parametersk=0.10;B=12.0;// Forced Duffing equation, x=x(1), y=x(2)functiondx=DUFF(t,x)dx(1)=x(2);dx(2)=-k*x(2)-x(1)^3+B*cos(t);endfunction// The time range and step for calculationNN=10000;Tmax=NN*2*%pi;t=linspace(0,Tmax,NN+1);// The initial values and ode solverx0=3;y0=0.1;X0=[x0;y0];X1=ode(X0,0,t,DUFF);csvWrite(X1.','DUFF_XY.csv')csvWrite(t.','DUFF_T.csv')