def read_fas_file(fas_file):
    """
    Reads FAS file and returns freq and fas arrays
    """
    freqs = []
    fas = []

    # Read input file
    input_file = open(fas_file, 'r')
    # Skip headers
    for line in input_file:
        line = line.strip()
        # skip blank lines
        if not line:
            continue
        if line.startswith("freq"):
            break
    for line in input_file:
        line = line.strip()
        # skip blank lines
        if not line:
            continue
        pieces = line.split()
        pieces = [float(piece) for piece in pieces]
        freqs.append(pieces[0])
        fas.append(pieces[1])
    # All done!
    input_file.close()

    return freqs, fas