#!/usr/bin/python3.6

import matplotlib
import numpy as np
import matplotlib.pyplot as plt
import scipy.fftpack

# Number of samplepoints
N = 50000
# sample spacing
T = 1.0 / 10000000
x = np.linspace(0.0, N * T, N)
y = np.sin(100000.0 * 2.0 * np.pi * x) * np.exp(-x / 0.0005)  # + 0.5*np.sin(80.0 * 2.0*np.pi*x)
#y[0:5000] = 0
yf = scipy.fftpack.fft(y)
xf = np.linspace(0.0, 1.0 / (2.0 * T), N // 2)
yr = scipy.fftpack.ifft(yf)
yb = yr.real

fig, ax = plt.subplots()
# ax.scatter(xf, 2.0/N * np.abs(yf[:N//2]))
ax.plot(xf[:512], 2.0 / N * np.abs(yf[:512]))
# ax.plot(x, y)
print(abs(yf)[:512])

plt.show()