#!/usr/bin/env python3

import sys

import numpy as np
import matplotlib.pyplot as pp

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)

    pp.plot(np.real(data), np.imag(data), 'x')

    a = np.linspace(-np.pi, np.pi, 200)
    pp.plot(np.cos(a), np.sin(a), 'k--', linewidth=0.7)
    pp.plot([1, 1, -1, -1, 1], [1, -1, -1, 1, 1], 'k--', linewidth=0.7)
    pp.plot([-1.5, 1.5], [0, 0], 'k--', linewidth=0.7)
    pp.plot([0, 0], [-1.5, 1.5], 'k--', linewidth=0.7)
    pp.xlim([-1.5, 1.5])
    pp.ylim([-1.5, 1.5])
    pp.axis('equal')
    pp.show()