45 lines
966 B
Python
45 lines
966 B
Python
|
#!/usr/bin/env python3
|
||
|
|
|
||
|
|
import sys
|
||
|
|
|
||
|
|
import numpy as np
|
||
|
|
import matplotlib.pyplot as pp
|
||
|
|
|
||
|
|
from matplotlib.animation import FuncAnimation
|
||
|
|
|
||
|
|
def load_data():
|
||
|
|
with open(sys.argv[1], 'rb') as infile:
|
||
|
|
header = infile.read(4)
|
||
|
|
if header != b'CPX_':
|
||
|
|
print(f"Error: not a complex signal file. Format {header} not implemented yet.")
|
||
|
|
exit(1)
|
||
|
|
|
||
|
|
T = np.fromfile(infile, dtype=np.float32, count=1)
|
||
|
|
data = np.fromfile(infile, dtype=np.complex64)
|
||
|
|
|
||
|
|
f = np.arange(-1/(2*T), 1/(2*T), 1/T/data.size)[:data.size]
|
||
|
|
|
||
|
|
spec = 20*np.log10(np.absolute(np.fft.fftshift(np.fft.fft(data))) / data.size)
|
||
|
|
|
||
|
|
return spec, f
|
||
|
|
|
||
|
|
|
||
|
|
fig = pp.figure()
|
||
|
|
ax = pp.subplot()
|
||
|
|
|
||
|
|
spec, f = load_data()
|
||
|
|
|
||
|
|
line, = ax.plot(f, spec, 'b-')
|
||
|
|
|
||
|
|
ax.legend(['Spectrum'])
|
||
|
|
ax.set_xlabel('Frequency [Hz]')
|
||
|
|
|
||
|
|
def update(*args):
|
||
|
|
spec, f = load_data()
|
||
|
|
line.set_ydata(spec)
|
||
|
|
|
||
|
|
return [line]
|
||
|
|
|
||
|
|
anim = FuncAnimation(fig, update, interval=500)
|
||
|
|
pp.show()
|