title: Solving a nonlinear ODE 2. Order in Matlab numerically
body: <p>I have a nonlinear-ODE of the second order with trigonometric functions such that I cannot formulate it depending of the second derivation. For example:</p>
  
  <pre><code>ay'' + b arctan(y'') + cy' + dy=0
  y'(0)=0, y''(0)=0
  </code></pre>
  
  <p><strong>Without existence of</strong> a term like <strong>arctan(y'')</strong> I could write my ode function like</p>
  
  <pre><code>function output=myodefunc(u,t){
    y(1)=u(2);
    y(2)=(-c*u(2)-d*u(1))/m;
    output=y';
  }
  </code></pre>
  
  <p><strong>Unfortunately</strong> the nonlinear term of the second order (=> b*arctan(y'') ) makes me unable to write the ode <strong>in dependence of y''</strong> .</p>
  
  <p>Is there any way to solve such a trigonometric ode numerically in Matlab?</p>