Python TypeError: derivatives_circ() takes 2 positional arguments but 6 were given

Question

i am trying to calculate some derivatives in order to complete some equations. but when i define my function which i would like to hold 6 different variables. it gives me this error bellow.

  File "C:\\Users\\Leona\\Anaconda3\\lib\\site-packages\\spyder\\utils\\site\\sitecustomize.py", line 102, in execfile exec(compile(f.read(), filename, 'exec'), namespace) File "C:/Users/Leona/.matplotlib/Python_Dyn_Opdracht6_tweede.py", line 94, in <module> afgeleiden = derivatives_circ([theta[n], omega[n]], x[n], vx[n], y[n], vy[n], t[n]) TypeError: derivatives_circ() takes 2 positional arguments but 6 were given 

this is the code i used to create the function

 def derivatives_circ(state, t): theta = state[0] omega = state[1] Moment=F*D alpha = Moment/Ig x = state[2] vx = state[3] ax = F*np.cos(theta)/my = state[4] vy = state[5] ay = F*np.sin(theta)/m return [omega, alpha, vx, vy, ax, ay] resultaat = odeint(derivatives_circ,[theta0, omega0, x0, vx0, y0, vy0], t) theta = resultaat[:,0] omega = resultaat[:,1] x = resultaat[:,2] vx = resultaat[:,3] y = resultaat[:,4] vy = resultaat[:,5] for n in range(len(t)-1): if theta[n]<0.5*np.pi: afgeleiden = derivatives_circ([theta[n], omega[n]], x[n], vx[n], y[n], vy[n], t[n]) omega[n+1] = omega[n] + afgeleiden[1]*dt theta[n+1] = theta[n] + afgeleiden[0]*dt vx[n+1]=vx[n]+afgeleiden[3]*dt x[n+1]=x[n]+afgeleiden[2]*dt vy[n+1]=vy[n]+afgeleiden[5]*dt y[n+1]=y[n]+afgeleiden[4]*dt else: afgeleiden_circ = derivatives_circ([theta[n], omega[n]], x[n], vx[n], y[n], vy[n], t[n]) omega[n+1] = omega[n] + afgeleiden_circ[1]*dt theta[n+1] = theta[n] + afgeleiden_circ[0]*dt afgeleiden_lin = derivatives_circ([x[n],vx[n]],t[n]) vx[n+1]=vx[n]+afgeleiden[3]*dt x[n+1]=x[n]+afgeleiden[2]*dt afgeleiden = derivatives_circ([y[n],vy[n]],t[n]) vy[n+1]=vy[n]+afgeleiden_circ[5]*dt y[n+1]=y[n]+afgeleiden[4]*dt 

Any help would really be appreciated!

Answer 1

This line here:

afgeleiden = derivatives_circ([theta[n], omega[n]], x[n], vx[n], y[n], vy[n], t[n])

should maybe be:

afgeleiden = derivatives_circ([theta[n], omega[n], x[n], vx[n], y[n], vy[n]], t[n])

based on your earlier calls to derivatives_circ

Answer 2

In this line:

def derivatives_circ(state, t):

You defined this function so that it takes 2 arguments , but then in this line:

afgeleiden = derivatives_circ([theta[n], omega[n]], x[n], vx[n], y[n], vy[n], t[n])

You are giving it 6 arguments ! That's why it's giving you the error. I don't know the mentality behind your code, but replacing it with this line:

afgeleiden = derivatives_circ([theta[n], omega[n], x[n], vx[n], y[n], vy[n]], t[n])

Should work!