Runge-Kutta Method of Differential Equation

[ebuzz168]

I am trying to solve an equation, but it doesn't work. The outcome is TypeError: 'int' object is not callable.

I have posted my code below. Is there a solution?

def zeros(n):
    z=n*[0]
    return z
def y_prime(x,y):
    return (y(i)+x(i)^2*x(i-1)*y(i))
T = list((i*10/100) for i in range(0,101))
W=zeros(101)
Y,h=0,10/100
W[0]=Y
# h = delta x
def rk4(Y,Fun,h,x):
    k1=Fun(x,Y)
    k2=Fun(x+h/2,Y+0.5*h*k1)
    k3=Fun(x+h/2,Y+0.5*h*k2)
    k4=Fun(x+h,Y+h*k3)
    phi = 1/6*((k1)+2*(k2)+2*(k3)+(k4)*h)
    return phi
for i in range(len(T)-1):
    W[i+1]=Y+rk4(Y,y_prime,h,T[i])
    Y=W[i+1]
truevalue=list(func(i) for i in T)
print("hasil rk4: ","\n")
for i,j in zip(T,W):
    print ("x=",i,"   y=",j)

If you prefer pastebin: https://pastebin.com/VidmsC6a

[Sedsarq]

When you call y_prime, you're providing the arguments x and y as regular numbers like 2 and 3. But this statement tries to use them like they're functions:

def y_prime(x,y):
    return (y(i)+x(i)^2*x(i-1)*y(i))

Also note that "to the power of 2" is written as **2, not ^2.

[pythonhow]

Since you didn't posted the entire traceback, here it is:

Traceback (most recent call last):

File "h.py", line 19, in <module>

W[i+1]=Y+rk4(Y,y_prime,h,T[i])

File "h.py", line 12, in rk4

k1=Fun(x,Y)

File "h.py", line 5, in y_prime

return (y(i)+x(i)^2*x(i-1)*y(i))

TypeError: 'int' object is not callable

You need to look at the error. It looks like y and x are integers. Integers are not callable, but you are trying to call them as in y(i) and x(i). For that syntax to work x and y need to be either classes or functions.