Reputation: 797
I have a function that returns an array:
def fun(x,a):
return [a*x,a*x**2]
and I want to integrate it (using scipy quad
):
def integrate(a):
return quad(fun[0],0,1,args=a)
print integrate(1)
This gives TypeError: 'function' object is not subscriptable
.
What's the right, pythonic way to do this?
Upvotes: 1
Views: 470
Reputation: 47840
Your function returns an array, integrate.quad
needs a float to integrate. So you want to give it a function that returns one of the elements from your array instead of the function itself. You can do that via a quick lambda
:
def integrate(a, index=0)
return quad(lambda x,y: fun(x, y)[index], 0, 1, args=a)
Upvotes: 3
Reputation: 9887
Create a wrapper function around fun
to select an element of the array. For example, the following will integrate the first element of the array.
from scipy.integrate import quad
# The function you want to integrate
def fun(x, a):
return np.asarray([a * x, a * x * x])
# The wrapper function
def wrapper(x, a, index):
return fun(x, a)[index]
# The integration
quad(wrapper, 0, 1, args=(1, 0))
Following @RobertB's suggestion, you should avoid defining a function int
because it messes with the builtin names.
Upvotes: 5