When using scipy.optimize.fmin_bfgs I got TypeError: f() missing 1 required positional argument:
<p>I'm trying to calculate minima of the six-hump camelback function using scipy.optimize.fmin_bfgs() function. Here is my code: </p>

<pre><code>import numpy as np
import matplotlib.pyplot as plt
from scipy import optimize

def f(x,y):
    return (4 - 2.1*x**2 + x**4/3)*x**2 + x*y + (4*y**2 - 4)*y**2

x0 = [0,0]

optimize.fmin_bfgs(f, x0)
</code></pre>

<p>Output: </p>

<pre><code>TypeError: f() missing 1 required positional argument: 'y'
</code></pre>

<p>I guess there is something wrong with the way I pass x0?</p>