#!/usr/bin/env python
# encoding: utf-8

from numpy import cos, pi, linspace
import math

def sign(v):
    if v < 0.0:
        return -1.0
    elif v > 0.0:
        return 1.0
    return 0.0

def check(a=5.0, b=6.0, n=2.758):
    nr = 5
    line = []
    n2 = 2.0 / n
    for i in range(nr):
        t = i * pi * 2.0 / nr
        ct = cos(t)
        x = abs(ct ** n2) * a #* sign(ct)
        print(i, ct, x)
        line.append((x))
    return line

def check2(a=5.0, b=6.0, n=2.758):
    nr = 5
    line = []
    n2 = 2.0 / n
    for i in range(nr):
        t = i * math.pi * 2.0 / nr
        ct = math.cos(t)
        x = abs(ct ** n2) * a #* sign(ct)
        print(i, ct, x)
        line.append((x))
    return line

print('-'*30)

cc = [3.0]
print('cc', cc)


nn = 1
bb = [round(z, 2) for z in linspace(3.0, 3.0, nn)]
print('bb', bb)
print('-'*30)

for n in cc:
    print('n', n)
    print('check cc', check(n=n))

print('-'*30)

for n in bb:
    print('n', n)
    print('check bb', check(n=n))


print('-'*60)

for n in cc:
    print('n', n)
    print('check2 cc', check2(n=n))

print('-'*30)

for n in bb:
    print('n', n)
    print('check2 bb', check2(n=n))


'''
 ./nan-test.py
------------------------------
cc [3.0]
bb [3.0]
------------------------------
n 3.0
0 1.0 5.0
1 0.30901699437494745 2.285379077161093
./nan-test.py:21: RuntimeWarning: invalid value encountered in double_scalars
  x = abs(ct ** n2) * a #* sign(ct)
2 -0.8090169943749473 nan
3 -0.8090169943749475 nan
4 0.30901699437494723 2.285379077161092
check cc [5.0, 2.285379077161093, nan, nan, 2.285379077161092]
------------------------------
n 3.0
0 1.0 5.0
1 0.30901699437494745 2.285379077161093
2 -0.8090169943749473 nan
3 -0.8090169943749475 nan
4 0.30901699437494723 2.285379077161092
check bb [5.0, 2.285379077161093, nan, nan, 2.285379077161092]
------------------------------------------------------------
n 3.0
0 1.0 5.0
1 0.30901699437494745 2.285379077161093
2 -0.8090169943749473 4.341186402706317
3 -0.8090169943749475 4.341186402706317
4 0.30901699437494723 2.285379077161092
check2 cc [5.0, 2.285379077161093, 4.341186402706317, 4.341186402706317, 2.285379077161092]
------------------------------
n 3.0
0 1.0 5.0
1 0.30901699437494745 2.285379077161093
./nan-test.py:33: RuntimeWarning: invalid value encountered in double_scalars
  x = abs(ct ** n2) * a #* sign(ct)
2 -0.8090169943749473 nan
3 -0.8090169943749475 nan
4 0.30901699437494723 2.285379077161092
check2 bb [5.0, 2.285379077161093, nan, nan, 2.285379077161092]    
'''