title: Scipy Optimize Curve_fit error for bounds
body: <p>When I try to run:</p>
  
  <pre><code>bet = (nu[minimum],10**4,3000,0,0,5000)   # Array of initial bet parameters
  bound = ( (nu[0],nu[len(nu)-1]),(10**3,10**6),(-np.inf,np.inf),(-np.inf,np.inf),(-np.inf,np.inf),(-np.inf,np.inf) )
  popt,pcov = curve_fit(S_21,x,y, p0=bet, bounds = bound)
  </code></pre>
  
  <blockquote>
    <p>TypeError: leastsq() got an unexpected keyword argument 'bounds'</p>
  </blockquote>
  
  <p>What is the problem? I use Python 3.4.4 on Windows.</p>