import matplotlib.pyplot as plt
import numpy as np
import sys
import os

def plot_error(dir):
    # q | I_data | err | I_fit
    data = np.genfromtxt(os.path.join(dir, "POPC-test.fit"))

    plt.loglog(data[:,0], data[:, 1], ".", label="I_data")
    plt.loglog(data[:,0], data[:, 3], label="I_fit")

    plt.legend()

    plt.show()

if __name__ == "__main__":
    if len(sys.argv) > 1 and os.path.isdir(sys.argv[1]):
        dir = sys.argv[1]
    else:
        dir = "POPC-test"

    plot_error(dir)