title: Solving a system of odes (with changing constant!) using scipy.integrate.odeint?
body: <p>I currently have a system of odes with a time-dependent constant. E.g.</p>
  
  <pre><code>def fun(u, t, a, b, c):
      x = u[0]
      y = u[1]
      z = u[2]
      dx_dt = a * x + y * z
      dy_dt = b * (y-z)
      dz_dt = -x*y+c*y-z
      return [dx_dt, dy_dt, dz_dt]
  </code></pre>
  
  <p>The constants are "a", "b" and "c". I currently have a list of "a"s for every time-step which I would like to insert at every time-step, when using the scipy ode solver...is this possible?</p>
  
  <p>Thanks!</p>