#!/usr/bin/env python
# Copyright (C) 2015 Christopher M. Biwer
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
import logging
import numpy
import sys
from pycbc import frame
# import dependencies that are not standard to pycbc
from foton import Filter, iir2z
logger = logging.getLogger('pycbc.filter.fotonfilter')
[docs]
def get_swstat_bits(frame_filenames, swstat_channel_name, start_time, end_time):
''' This function just checks the first time in the SWSTAT channel
to see if the filter was on, it doesn't check times beyond that.
This is just for a first test on a small chunck of data.
To read the SWSTAT bits, reference: https://dcc.ligo.org/DocDB/0107/T1300711/001/LIGO-T1300711-v1.pdf
Bit 0-9 = Filter on/off switches for the 10 filters in an SFM.
Bit 10 = Filter module input switch on/off
Bit 11 = Filter module offset switch on/off
Bit 12 = Filter module output switch on/off
Bit 13 = Filter module limit switch on/off
Bit 14 = Filter module history reset momentary switch
'''
# read frames
swstat = frame.read_frame(frame_filenames, swstat_channel_name,
start_time=start_time, end_time=end_time)
# convert number in channel to binary
bits = bin(int(swstat[0]))
# check if filterbank input or output was off
filterbank_off = False
if len(bits) < 14 or int(bits[-13]) == 0 or int(bits[-11]) == 0:
filterbank_off = True
return bits[-10:], filterbank_off
[docs]
def filter_data(data, filter_name, filter_file, bits, filterbank_off=False,
swstat_channel_name=None):
'''
A naive function to determine if the filter was on at the time
and then filter the data.
'''
# if filterbank is off then return a time series of zeroes
if filterbank_off:
return numpy.zeros(len(data))
# loop over the 10 filters in the filterbank
for i in range(10):
# read the filter
filter = Filter(filter_file[filter_name][i])
# if bit is on then filter the data
bit = int(bits[-(i+1)])
if bit:
logger.info('filtering with filter module %d', i)
# if there are second-order sections then filter with them
if len(filter.sections):
data = filter.apply(data)
# else it is a filter with only gain so apply the gain
else:
coeffs = iir2z(filter_file[filter_name][i])
if len(coeffs) > 1:
logger.info(
'Gain-only filter module return more than one number'
)
sys.exit()
gain = coeffs[0]
data = gain * data
return data
[docs]
def read_gain_from_frames(frame_filenames, gain_channel_name, start_time, end_time):
'''
Returns the gain from the file.
'''
# get timeseries from frame
gain = frame.read_frame(frame_filenames, gain_channel_name,
start_time=start_time, end_time=end_time)
return gain[0]