import numpy as np
import math
from scipy.interpolate import lagrange
f = []
for j in range(5):
    x = -1 + j/2
    f = 1/np.cosh(math.pi*x)
    print("{",x,",",f,
########################################
a = np.array([-1.0 ,
              -0.5 ,
              0.0 ,
              0.5 ,
              1.0 ,])
b = np.array([0.08626673833405443 ,
              0.3985368153383867 ,
              1.0 ,
              0.3985368153383867 ,
              0.08626673833405443 ,
])
def my_range(start, end, step):
    while start <= end:
        yield start
        start += step

ok = lagrange(a,b)
print(ok,",")
#########################################
1.989 x^4 - 1.249e-16 x^3 - 2.903 x^2 - 2.255e-17 x^1 + 1 ,