# Revision history [back]

### Problem with quad from SciPy

I have a simple code that seems to work fine (although I cannot be sure when there are several constants like a13 that seem to be integration constants while the integrals are all definite?), at least runs with no error, when the symbolic "integral" function is used instead of "quad", but now using "quad" the code runs into error. This is an example code:

reset()
forget()

var('y')
var('kx')

alpha1=var('a11,a12,a13')

phi11(y)=y*(y-1);    phi12(y)=y*(y-1)*(y+1);    phi13(y)=y*(y-1)*(y^2+1)

phi1=[phi11,phi12,phi13]

U1(y)=sum(alpha1[j]*phi1[j](y) for j in range(3))

eq1=[

quadpack.error: Supplied function does not return a valid float.