#!/usr/bin/env python

from __future__ import print_function, division
import sys
import numpy as np
from scipy import signal
try: from future_builtins import zip
except ImportError:     # either before Python2.6 or one of the Python 3.*
    try: from itertools import izip as zip
    except ImportError: # not an early Python, so must be Python 3.*
        pass

sampling_freq = 20      # if not read from input

times=[]        # time stamps from first column
values=[]       # data values from second column
for line in sys.stdin:
    if line.startswith('#'):
        print (line.rstrip())
        if line.startswith('# Recording every'):
           # extract from input: # Recording every 0.05 sec (20.0 Hz)
           fields = line.split('(')
           sampling_freq=float(fields[1].split()[0])
        continue
    fields = [x for x in map(float, line.split())]
    if len(fields)>=2:
        times.append(fields[0])
        values.append(fields[1])

values=np.array(values)  # needed because sosfiltfilt omits the cast

# define the corner frequencies
low_end_cutoff = 0.3    # Hz
lo_end_over_Nyquist = low_end_cutoff/(0.5*sampling_freq)
high_end_cutoff = 6.0 # Hz
hi_end_over_Nyquist = high_end_cutoff/(0.5*sampling_freq)

# band-pass filter passes frequencies between low_end_cutoff and high_end_cutoff
sos_band = signal.iirfilter(4,
            Wn=[lo_end_over_Nyquist,hi_end_over_Nyquist],
                            btype="bandpass", ftype='bessel', output='sos')
bandpass = signal.sosfiltfilt(sos_band, values)

# low-pass filter passes frequencies below low_end_cutoff
sos_low = signal.iirfilter(4, Wn=[lo_end_over_Nyquist],
                           btype="lowpass", ftype='bessel', output='sos')
lowpass = signal.sosfiltfilt(sos_low, values)

print("# Bessel bandpass to {:.3g}Hz to {:.3g}Hz".format(low_end_cutoff, high_end_cutoff))
print("# Bessel lowpass {:.3g}Hz".format(low_end_cutoff))

for t,v,b,l in zip(times,values,bandpass,lowpass):
    print("{:.7f}\t{:.6f}\t{:.6f}\t{:.6f}".format(t,v,b,l))