My function does not take floats: - "TypeError('only size-1 arrays can be converted to Python scalars')" (I think it has a quick fix!)

Question

I wrote a code to use Riemann to calculate the area under certain function. It works well but when I set the boundaries to decimal number I get an error. I think I should tell the function I want to be able to enter floats but I don't see how. I think it is an easy fix, hope someone can help me:

import numpy as np
import math

def func(x):
    return x ** 2

def func1(x):
    return x ** (x +0.5)

def func2(x):
    return np.sin(x)

def func3(x):
    return np.sin(x ** 2)

def riemann(f,a,b,N):
    dx = (b-a)/N
    x_midpoint = np.linspace(dx/2,b - dx/2,N)
    riemann_sum = np.sum(f(x_midpoint) * dx)
    return riemann_sum

res = riemann(func,0,1,10000)
res1 = riemann(func1,0,1,10000)
res2 = riemann(func2,0,1,10000)
res3 = riemann(func3,0,1,10000)


print("Midpoint Riemann Sum:",res)
print("Midpoint Riemann Sum:",res1)
print("Midpoint Riemann Sum:",res2)
print("Midpoint Riemann Sum:",res3)

Answer 1

Got the followin output and no error found:

Midpoint Riemann Sum: 0.3333333325
Midpoint Riemann Sum: 0.527737838955
Midpoint Riemann Sum: 0.459697694323
Midpoint Riemann Sum: 0.310268301273

What can we do to reproduce the error ?

EDIT:

using a and b as decimals:

res = riemann(func,0.2,3.14,10000)
res1 = riemann(func1,0.2,3.14,10000)
res2 = riemann(func2,0.2,3.14,10000)
res3 = riemann(func3,0.2,3.14,10000)

OUTPUT:

Midpoint Riemann Sum: 9.66243875102
Midpoint Riemann Sum: 27.9239376537
Midpoint Riemann Sum: 1.87259837142
Midpoint Riemann Sum: 0.724064617658

and still got no error :/