If statement check mistake - python-3.x

Question

I had a code with if statements and the code found the cosine value of the user-defined angle in radial. I typed the code to Taylor Series up to 12!. The code is;
import numpy as np
import matplotlib.pyplot as plt
import math
teta = np.arange(-8*np.pi, 8*np.pi+0.1,0.1)
P_ = [None]*len(teta)
ang_ = np.zeros(len(teta))
def func(teta):
for i in range(len(teta)):
if teta[i]<=0:
if abs(teta[i])%np.pi>=np.pi:
ang_[i] = (abs(teta[i])%(2*np.pi)-2*np.pi)*(-1)
else:
ang_[i] = (abs(teta[i])%(2*np.pi))*(-1)
else:
if teta[i]%2*np.pi >= np.pi:
ang_[i] = teta[i] % (2*np.pi) - 2*np.pi
else:
ang_[i] = teta[i] % (2*np.pi)
P_[i] = 1 - (1/2)*((ang_[i])**2) + (1/math.factorial(4))*((ang_[i])**4) - (1/math.factorial(6))*((ang_[i])**6) + (1/math.factorial(8))*((ang_[i])**8) - (1/math.factorial(10))*((ang_[i])**10) + (1/math.factorial(12))*((ang_[i])**12)
return P_
plt.plot(teta, func(teta), "b:+")
plt.plot(teta, np.cos(teta), "k--")
plt.grid()
plt.show
And the code cannot calculate when the teta angle is greater than 6 or -6. when I checked the code by debugging the step, that teta angle is -6.18319, jump over if statement
if abs(teta[i])%2*np.pi >= np.pi and teta[i]<-np.pi:
and jumps into
elif abs(teta[i])%np.pi >= 0 and teta[i]<0:
and code transverse the teta value to another angle array named ang_, and it determines by
ang_[i] = (abs(teta[i])%(2*np.pi))*(-1)
Thus the result of the function is over 2.
I will be glad if you would help me. Thanks a lot.

Answer 1

I found the mistake and the correct code is;
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Tue Mar 1 13:54:51 2022
#author: burak
"""
import numpy as np
import matplotlib.pyplot as plt
import math
user_degree = int(input('cosine value of angle in degree')) / 180 * np.pi
teta = np.arange(-user_degree, user_degree+0.1,0.1)
P_ = [None]*len(teta)
ang_ = np.zeros(len(teta))
def func(teta):
for i in range(len(teta)):
if teta[i]<=0:
teta = abs(teta)
if teta[i]%(2*np.pi) >= np.pi:
ang_[i] = (teta[i]%(2*np.pi)) - 2 * np.pi
else:
ang_[i] = (teta[i]%(2*np.pi))
else:
if teta[i]%(2*np.pi) >= np.pi:
ang_[i] = teta[i] % (2*np.pi) - 2 * np.pi
else:
ang_[i] = teta[i] % (2*np.pi)
P_[i] = 1 - (1/2)*((ang_[i])**2) + (1/math.factorial(4))*((ang_[i])**4) - (1/math.factorial(6))*((ang_[i])**6) + (1/math.factorial(8))*((ang_[i])**8) - (1/math.factorial(10))*((ang_[i])**10) + (1/math.factorial(12))*((ang_[i])**12)
return P_
plt.plot(teta, func(teta), "b:+")
plt.plot(teta, np.cos(teta), "k--")
plt.grid()
plt.show
The purpose of this code is to obtain correct cosine values of given angle. I asked the qs that the code cannot step to the correct if condition. for example when the angle is greater than np.pi the resul was above 1. I changed the code as when the angle is lesser than zero and greater than np.pi, code calculates absolute value of angle. Then the step moves to the correct condition. The next calculation is when the absolute value of teta greater then np.pi, the code substructs np.pi. At last the Taylor Series calculation matched with the np.cos() calculation.