def project_waveform(Hlm, theta, phi, distance=20.0):
"""
Project the expansion parameters in the dictionary Hlm onto the sky for
co-latitude theta, azimuth phi.
Returns hplus, hcross for a given theta, phi
"""
colatitude_indices=[2]
azimuth_indices=[-2,2]
hplus=0.0
hcross=0.0
h = np.zeros(len(Hlm['l=2, m=2']), dtype=complex)
# See e.g., pycbc/waveform/nr_waveform.py
for l in colatitude_indices:
for m in azimuth_indices:
sYlm = lal.SpinWeightedSphericalHarmonic(theta, phi, -2, l, m)
curr_Hlm = Hlm['l=%i, m=%i'%(l, m)]
# h+=curr_Hlm * sYlm
curr_hp = curr_Hlm.real * sYlm.real - curr_Hlm.imag * sYlm.imag
curr_hc = -curr_Hlm.real*sYlm.imag - curr_Hlm.imag * sYlm.real
hplus += curr_hp
hcross += curr_hc
# hplus = h.real
# hcross = -1*h.imag
# Scale by distance
distance*=1e6*lal.PC_SI
hplus /= distance
hcross /= distance
# Scale up by 40% for quadrupole approximation
hplus*=1.4
hcross*=1.4
#hplus = taper_start(hplus)
#hcross = taper_start(hcross)
# Window:
window = lal.CreateTukeyREAL8Window(len(hplus), 0.1)
#hplus *= window.data.data
#hcross *= window.data.data
hplus = pycbc.types.TimeSeries(initial_array=hplus, delta_t = 1.0/16384)
hcross = pycbc.types.TimeSeries(initial_array=hcross, delta_t = 1.0/16384)
return hplus, hcross
def make_windows(n, kaiser_beta, creighton_beta, tukey_beta, gauss_beta):
return {
"rectangle": lal.CreateRectangularREAL8Window(n),
"Hann": lal.CreateHannREAL8Window(n),
"Welch": lal.CreateWelchREAL8Window(n),
"Bartlett": lal.CreateBartlettREAL8Window(n),
"Parzen": lal.CreateParzenREAL8Window(n),
"Papoulis": lal.CreatePapoulisREAL8Window(n),
"Hamming": lal.CreateHammingREAL8Window(n),
"Kaiser": lal.CreateKaiserREAL8Window(n, kaiser_beta),
"Creighton": lal.CreateCreightonREAL8Window(n, creighton_beta),
"Tukey": lal.CreateTukeyREAL8Window(n, tukey_beta),
"Gauss": lal.CreateGaussREAL8Window(n, gauss_beta)
}
def calculate_spectral_correlation(fft_window_len,wtype='hann',window_fraction=None):
"""
Calculate the two point spectral correlation introduced by windowing
the data before transforming to the frequency domain -- valid choices
are 'hann' and 'tukey'. The window_fraction parameter only has meaning
for wtype='tukey'.
"""
print "|- Whitening window and spectral correlation..."
if wtype == 'hann':
window = lal.CreateHannREAL8Window(fft_window_len)
elif wtype == 'tukey':
window = lal.CreateTukeyREAL8Window(fft_window_len, window_fraction)
else:
raise ValueError("Can't handle window type %s" % wtype)
fft_plan = lal.CreateForwardREAL8FFTPlan(len(window.data.data), 1)
return window, lal.REAL8WindowTwoPointSpectralCorrelation(window, fft_plan)
def condition_imr_template(approximant, data, epoch_time, sample_rate_max,
max_ringtime):
assert -len(
data
) / sample_rate_max <= epoch_time < 0.0, "Epoch returned follows a different convention"
# find the index for the peak sample using the epoch returned by
# the waveform generator
epoch_index = -int(epoch_time * sample_rate_max) - 1
# align the peaks according to an overestimate of max rinddown
# time for a given split bank
target_index = len(data) - 1 - int(sample_rate_max * max_ringtime)
# rotate phase so that sample with peak amplitude is real
phase = numpy.arctan2(data[epoch_index].imag, data[epoch_index].real)
data *= numpy.exp(-1.j * phase)
data = numpy.roll(data, target_index - epoch_index)
# re-taper the ends of the waveform that got cyclically permuted
# around the ring
tukey_beta = 2. * abs(target_index - epoch_index) / float(len(data))
assert 0. <= tukey_beta <= 1., "waveform got rolled WAY too much"
data *= lal.CreateTukeyREAL8Window(len(data), tukey_beta).data.data
# done
return data, target_index
def hlmoft(self,
force_T=False,
deltaT=1. / 16384,
time_over_M_zero=0.,
taper_start_time=True):
"""
hlmoft uses stored interpolated values for hlm(t) generated via the standard cleaning process, scaling them
to physical units for use in injection code.
If the time window is sufficiently short, the result is NOT tapered (!!) -- no additional tapering is applied
The code will ALWAYS have zero padding on the end -- half of the buffer is zero padding!
This can cause loss of frequency content if you are not careful
"""
hlmT = {}
# Define units
m_total_s = MsunInSec * (self.P.m1 + self.P.m2) / lal.MSUN_SI
distance_s = self.P.dist / lal.C_SI # insures valid units. Default distance is 1 Mpc !
# Create a suitable set of time samples. Zero pad to 2^n samples.
# Note waveform is stored in s already
T_estimated = np.real(self.waveform_modes_complex[(2, 2)][-1, 0] -
self.waveform_modes_complex[(2, 2)][0, 0])
npts = 0
n_crit = 0
if not force_T:
npts_estimated = int(T_estimated / deltaT)
# print " Estimated length: ",npts_estimated, T_estimated
npts = lalsimutils.nextPow2(npts_estimated)
else:
npts = int(force_T / deltaT)
print(" Forcing length T=", force_T, " length ", npts)
# WARNING: Time range may not cover the necessary time elements.
# Plan on having a few seconds buffer at the end
T_buffer_required = npts * deltaT
print(" EOB internal: Estimated time window (sec) ", T_estimated,
" versus buffer duration ", T_buffer_required)
print(" EOB internal: Requested size vs buffer size", npts,
len(self.waveform_modes_complex[(2, 2)]))
# If the waveform is longer than the buffer, we need to avoid wraparound
# If the buffer requested is SHORTER than the 2*waveform, work backwards
# If the buffer requested is LONGER than the waveform, work forwards from the start of all data
fac_safety = 1 # Previously had used a factor of 2 for safety. but this can accidentally truncate the waveform at too high an fmin. Remove.
if T_buffer_required / fac_safety > T_estimated:
tvals = np.arange(npts) * deltaT + float(
self.waveform_modes_complex[(2, 2)][0, 0]
) # start at time t=0 and go forwards (zeros automatically padded by interpolation code)
t_crit = float(-self.waveform_modes_complex[(2, 2)][0, 0])
n_crit = int(
t_crit / deltaT
) # estiamted peak sample location in the t array, working forward
else:
print(
" EOB internal: Warning LOSSY conversion to insure half of data is zeros "
)
# Create time samples by walking backwards from the last sample of the waveform, a suitable duration
# ASSUME we are running in a configuration with align_at_peak_l2m2_emission
# FIXME: Change this
tvals = T_buffer_required / fac_safety + (
-npts + 1 + np.arange(npts)) * deltaT + np.real(
self.waveform_modes_complex[
(2, 2)][-1, 0]) # last insures we get some ringdown
t_crit = T_buffer_required / fac_safety - (np.real(
self.waveform_modes_complex[(2, 2)][-1, 0]))
n_crit = int(t_crit / deltaT)
# if rosDebug:
# print " time range being sampled ", [min(tvals),max(tvals)], " corresponding to dimensionless range", [min(tvals)/m_total_s,max(tvals)/m_total_s]
# print " estimated peak sample at ", n_crit
# Loop over all modes in the system
for mode in self.waveform_modes_complex.keys():
amp_vals = m_total_s / distance_s * self.waveform_modes_complex_interpolated_amplitude[
mode](tvals) # vectorized interpolation with piecewise
phase_vals = self.waveform_modes_complex_interpolated_phase[mode](
tvals)
phase_vals = lalsimutils.unwind_phase(
phase_vals) # should not be necessary, but just in case
if rosDebug:
print(" Mode ", mode, " physical strain max, indx,",
np.max(amp_vals), np.argmax(amp_vals))
# Copy into a new LIGO time series object
wfmTS = lal.CreateCOMPLEX16TimeSeries(
"h", lal.LIGOTimeGPS(0.), 0., deltaT,
lalsimutils.lsu_DimensionlessUnit, npts)
wfmTS.data.data[:] = 0 # lal initialization is sometimes ratty.
wfmTS.data.data = amp_vals * np.exp(1j * phase_vals)
# Set the epoch for the time series correctly: should have peak near center of series by construction
# note all have the same length
# wfmTS.epoch = -deltaT*wfmTS.data.length/2 # did not work
#n_crit = np.argmax(wfmTS.data.data)
#print n_crit*wfmTS.deltaT, wfmTS.epoch # this should be nearly zero
# taper the start (1s. Only needed if I do not grab the whole range, because I taper the raw data)
if taper_start_time:
tTaper = 1
nTaper = int(tTaper / deltaT)
hoft_window = lal.CreateTukeyREAL8Window(nTaper * 2, 0.8)
factorTaper = hoft_window.data.data[0:nTaper]
wfmTS.data.data[:nTaper] *= factorTaper
# Store the resulting mode
hlmT[mode] = wfmTS
# Set time at peak of 22 mode. This is a hack, but good enough for us
# n_crit = np.argmax(hlmT[(2,2)].data.data)
epoch_crit = float(-t_crit) #-deltaT*n_crit
print(" EOB internal: zero epoch sample location", n_crit,
np.argmax(np.abs(hlmT[(2, 2)].data.data)))
for mode in hlmT:
hlmT[mode].epoch = epoch_crit
return hlmT
def excess_power2(
ts_data, # Time series from magnetic field data
psd_segment_length, # Length of each segment in seconds
psd_segment_stride, # Separation between 2 consecutive segments in seconds
psd_estimation, # Average method
window_fraction, # Withening window fraction
tile_fap, # Tile false alarm probability threshold in Gaussian noise.
station, # Station
nchans=None, # Total number of channels
band=None, # Channel bandwidth
fmin=0, # Lowest frequency of the filter bank.
fmax=None, # Highest frequency of the filter bank.
max_duration=None, # Maximum duration of the tile
wtype='tukey'): # Whitening type, can tukey or hann
"""
Perform excess-power search analysis on magnetic field data.
This method will produce a bunch of time-frequency plots for every
tile duration and bandwidth analysed as well as a XML file identifying
all the triggers found in the selected data within the user-defined
time range.
Parameters
----------
ts_data : TimeSeries
Time Series from magnetic field data
psd_segment_length : float
Length of each segment in seconds
psd_segment_stride : float
Separation between 2 consecutive segments in seconds
psd_estimation : string
Average method
window_fraction : float
Withening window fraction
tile_fap : float
Tile false alarm probability threshold in Gaussian noise.
nchans : int
Total number of channels
band : float
Channel bandwidth
fmin : float
Lowest frequency of the filter bank.
fmax : float
Highest frequency of the filter bank
"""
# Determine sampling rate based on extracted time series
sample_rate = ts_data.sample_rate
# Check if tile maximum frequency is not defined
if fmax is None or fmax > sample_rate / 2.:
# Set the tile maximum frequency equal to the Nyquist frequency
# (i.e. half the sampling rate)
fmax = sample_rate / 2.0
# Check whether or not tile bandwidth and channel are defined
if band is None and nchans is None:
# Exit program with error message
exit("Either bandwidth or number of channels must be specified...")
else:
# Check if tile maximum frequency larger than its minimum frequency
assert fmax >= fmin
# Define spectral band of data
data_band = fmax - fmin
# Check whether tile bandwidth or channel is defined
if band is not None:
# Define number of possible filter bands
nchans = int(data_band / band) - 1
elif nchans is not None:
# Define filter bandwidth
band = data_band / nchans
nchans = nchans - 1
# Check if number of channels is superior than unity
assert nchans > 1
# Print segment information
print '|- Estimating PSD from segments of time',
print '%.2f s in length, with %.2f s stride...' % (psd_segment_length,
psd_segment_stride)
# Convert time series as array of float
data = ts_data.astype(numpy.float64)
# Define segment length for PSD estimation in sample unit
seg_len = int(psd_segment_length * sample_rate)
# Define separation between consecutive segments in sample unit
seg_stride = int(psd_segment_stride * sample_rate)
# Calculate the overall PSD from individual PSD segments
fd_psd = psd.welch(data,
avg_method=psd_estimation,
seg_len=seg_len,
seg_stride=seg_stride)
# We need this for the SWIG functions...
lal_psd = fd_psd.lal()
# Plot the power spectral density
plot_spectrum(fd_psd)
# Create whitening window
print "|- Whitening window and spectral correlation..."
if wtype == 'hann':
window = lal.CreateHannREAL8Window(seg_len)
elif wtype == 'tukey':
window = lal.CreateTukeyREAL8Window(seg_len, window_fraction)
else:
raise ValueError("Can't handle window type %s" % wtype)
# Create FFT plan
fft_plan = lal.CreateForwardREAL8FFTPlan(len(window.data.data), 1)
# Perform two point spectral correlation
spec_corr = lal.REAL8WindowTwoPointSpectralCorrelation(window, fft_plan)
# Initialise filter bank
print "|- Create filter..."
filter_bank, fdb = [], []
# Loop for each channels
for i in range(nchans):
channel_flow = fmin + band / 2 + i * band
channel_width = band
# Create excess power filter
lal_filter = lalburst.CreateExcessPowerFilter(channel_flow,
channel_width, lal_psd,
spec_corr)
filter_bank.append(lal_filter)
fdb.append(Spectrum.from_lal(lal_filter))
# Calculate the minimum bandwidth
min_band = (len(filter_bank[0].data.data) - 1) * filter_bank[0].deltaF / 2
# Plot filter bank
plot_bank(fdb)
# Convert filter bank from frequency to time domain
print "|- Convert all the frequency domain to the time domain..."
tdb = []
# Loop for each filter's spectrum
for fdt in fdb:
zero_padded = numpy.zeros(int((fdt.f0 / fdt.df).value) + len(fdt))
st = int((fdt.f0 / fdt.df).value)
zero_padded[st:st + len(fdt)] = numpy.real_if_close(fdt.value)
n_freq = int(sample_rate / 2 / fdt.df.value) * 2
tdt = numpy.fft.irfft(zero_padded, n_freq) * math.sqrt(sample_rate)
tdt = numpy.roll(tdt, len(tdt) / 2)
tdt = TimeSeries(tdt,
name="",
epoch=fdt.epoch,
sample_rate=sample_rate)
tdb.append(tdt)
# Plot time series filter
plot_filters(tdb, fmin, band)
# Compute the renormalization for the base filters up to a given bandwidth.
mu_sq_dict = {}
# Loop through powers of 2 up to number of channels
for nc_sum in range(0, int(math.log(nchans, 2))):
nc_sum = 2**nc_sum - 1
print "|- Calculating renormalization for resolution level containing %d %fHz channels" % (
nc_sum + 1, min_band)
mu_sq = (nc_sum + 1) * numpy.array([
lalburst.ExcessPowerFilterInnerProduct(f, f, spec_corr, None)
for f in filter_bank
])
# Uncomment to get all possible frequency renormalizations
#for n in xrange(nc_sum, nchans): # channel position index
for n in xrange(nc_sum, nchans, nc_sum + 1): # channel position index
for k in xrange(0, nc_sum): # channel sum index
# FIXME: We've precomputed this, so use it instead
mu_sq[n] += 2 * lalburst.ExcessPowerFilterInnerProduct(
filter_bank[n - k], filter_bank[n - 1 - k], spec_corr,
None)
#print mu_sq[nc_sum::nc_sum+1]
mu_sq_dict[nc_sum] = mu_sq
# Create an event list where all the triggers will be stored
event_list = lsctables.New(lsctables.SnglBurstTable, [
'start_time', 'start_time_ns', 'peak_time', 'peak_time_ns', 'duration',
'bandwidth', 'central_freq', 'chisq_dof', 'confidence', 'snr',
'amplitude', 'channel', 'ifo', 'process_id', 'event_id', 'search',
'stop_time', 'stop_time_ns'
])
# Create repositories to save TF and time series plots
os.system('mkdir -p segments/time-frequency')
os.system('mkdir -p segments/time-series')
# Define time edges
t_idx_min, t_idx_max = 0, seg_len
while t_idx_max <= len(ts_data):
# Define starting and ending time of the segment in seconds
start_time = ts_data.start_time + t_idx_min / float(
ts_data.sample_rate)
end_time = ts_data.start_time + t_idx_max / float(ts_data.sample_rate)
print "\n|-- Analyzing block %i to %i (%.2f percent)" % (
start_time, end_time, 100 * float(t_idx_max) / len(ts_data))
# Model a withen time series for the block
tmp_ts_data = types.TimeSeries(ts_data[t_idx_min:t_idx_max] *
window.data.data,
delta_t=1. / ts_data.sample_rate,
epoch=start_time)
# Save time series in relevant repository
segfolder = 'segments/%i-%i' % (start_time, end_time)
os.system('mkdir -p ' + segfolder)
plot_ts(tmp_ts_data,
fname='segments/time-series/%i-%i.png' %
(start_time, end_time))
# Convert times series to frequency series
fs_data = tmp_ts_data.to_frequencyseries()
print "|-- Frequency series data has variance: %s" % fs_data.data.std(
)**2
# Whitening (FIXME: Whiten the filters, not the data)
fs_data.data /= numpy.sqrt(fd_psd) / numpy.sqrt(2 * fd_psd.delta_f)
print "|-- Whitened frequency series data has variance: %s" % fs_data.data.std(
)**2
print "|-- Create time-frequency plane for current block"
# Return the complex snr, along with its associated normalization of the template,
# matched filtered against the data
#filter.matched_filter_core(types.FrequencySeries(tmp_filter_bank,delta_f=fd_psd.delta_f),
# fs_data,h_norm=1,psd=fd_psd,low_frequency_cutoff=filter_bank[0].f0,
# high_frequency_cutoff=filter_bank[0].f0+2*band)
print "|-- Filtering all %d channels..." % nchans
# Initialise 2D zero array
tmp_filter_bank = numpy.zeros(len(fd_psd), dtype=numpy.complex128)
# Initialise 2D zero array for time-frequency map
tf_map = numpy.zeros((nchans, seg_len), dtype=numpy.complex128)
# Loop over all the channels
for i in range(nchans):
# Reset filter bank series
tmp_filter_bank *= 0.0
# Index of starting frequency
f1 = int(filter_bank[i].f0 / fd_psd.delta_f)
# Index of ending frequency
f2 = int((filter_bank[i].f0 + 2 * band) / fd_psd.delta_f) + 1
# (FIXME: Why is there a factor of 2 here?)
tmp_filter_bank[f1:f2] = filter_bank[i].data.data * 2
# Define the template to filter the frequency series with
template = types.FrequencySeries(tmp_filter_bank,
delta_f=fd_psd.delta_f,
copy=False)
# Create filtered series
filtered_series = filter.matched_filter_core(
template,
fs_data,
h_norm=None,
psd=None,
low_frequency_cutoff=filter_bank[i].f0,
high_frequency_cutoff=filter_bank[i].f0 + 2 * band)
# Include filtered series in the map
tf_map[i, :] = filtered_series[0].numpy()
# Plot spectrogram
plot_spectrogram(numpy.abs(tf_map).T,
tmp_ts_data.delta_t,
band,
ts_data.sample_rate,
start_time,
end_time,
fname='segments/time-frequency/%i-%i.png' %
(start_time, end_time))
# Loop through all summed channels
for nc_sum in range(0, int(math.log(nchans, 2)))[::-1]:
nc_sum = 2**nc_sum - 1
mu_sq = mu_sq_dict[nc_sum]
# Clip the boundaries to remove window corruption
clip_samples = int(psd_segment_length * window_fraction *
ts_data.sample_rate / 2)
# Constructing tile and calculate their energy
print "\n|--- Constructing tile with %d summed channels..." % (
nc_sum + 1)
# Current bandwidth of the time-frequency map tiles
df = band * (nc_sum + 1)
dt = 1.0 / (2 * df)
# How much each "step" is in the time domain -- under sampling rate
us_rate = int(round(dt / ts_data.delta_t))
print "|--- Undersampling rate for this level: %f" % (
ts_data.sample_rate / us_rate)
print "|--- Calculating tiles..."
# Making independent tiles
# because [0:-0] does not give the full array
tf_map_temp = tf_map[:,clip_samples:-clip_samples:us_rate] \
if clip_samples > 0 else tf_map[:,::us_rate]
tiles = tf_map_temp.copy()
# Here's the deal: we're going to keep only the valid output and
# it's *always* going to exist in the lowest available indices
stride = nc_sum + 1
for i in xrange(tiles.shape[0] / stride):
numpy.absolute(tiles[stride * i:stride * (i + 1)].sum(axis=0),
tiles[stride * (i + 1) - 1])
tiles = tiles[nc_sum::nc_sum + 1].real**2 / mu_sq[nc_sum::nc_sum +
1].reshape(
-1, 1)
print "|--- TF-plane is %dx%s samples" % tiles.shape
print "|--- Tile energy mean %f, var %f" % (numpy.mean(tiles),
numpy.var(tiles))
# Define maximum number of degrees of freedom and check it larger or equal to 2
max_dof = 32 if max_duration == None else 2 * max_duration * df
assert max_dof >= 2
# Loop through multiple degrees of freedom
for j in [2**l for l in xrange(0, int(math.log(max_dof, 2)))]:
# Duration is fixed by the NDOF and bandwidth
duration = j * dt
print "\n|----- Explore signal duration of %f s..." % duration
print "|----- Summing DOF = %d ..." % (2 * j)
tlen = tiles.shape[1] - 2 * j + 1 + 1
dof_tiles = numpy.zeros((tiles.shape[0], tlen))
sum_filter = numpy.array([1, 0] * (j - 1) + [1])
for f in range(tiles.shape[0]):
# Sum and drop correlate tiles
dof_tiles[f] = fftconvolve(tiles[f], sum_filter, 'valid')
print "|----- Summed tile energy mean: %f, var %f" % (
numpy.mean(dof_tiles), numpy.var(dof_tiles))
plot_spectrogram(
dof_tiles.T,
dt,
df,
ts_data.sample_rate,
start_time,
end_time,
fname='segments/%i-%i/tf_%02ichans_%02idof.png' %
(start_time, end_time, nc_sum + 1, 2 * j))
threshold = scipy.stats.chi2.isf(tile_fap, j)
print "|------ Threshold for this level: %f" % threshold
spant, spanf = dof_tiles.shape[1] * dt, dof_tiles.shape[0] * df
print "|------ Processing %.2fx%.2f time-frequency map." % (
spant, spanf)
# Since we clip the data, the start time needs to be adjusted accordingly
window_offset_epoch = fs_data.epoch + psd_segment_length * window_fraction / 2
window_offset_epoch = LIGOTimeGPS(float(window_offset_epoch))
for i, j in zip(*numpy.where(dof_tiles > threshold)):
event = event_list.RowType()
# The points are summed forward in time and thus a `summed point' is the
# sum of the previous N points. If this point is above threshold, it
# corresponds to a tile which spans the previous N points. However, the
# 0th point (due to the convolution specifier 'valid') is actually
# already a duration from the start time. All of this means, the +
# duration and the - duration cancels, and the tile 'start' is, by
# definition, the start of the time frequency map if j = 0
# FIXME: I think this needs a + dt/2 to center the tile properly
event.set_start(window_offset_epoch + float(j * dt))
event.set_stop(window_offset_epoch + float(j * dt) +
duration)
event.set_peak(event.get_start() + duration / 2)
event.central_freq = filter_bank[
0].f0 + band / 2 + i * df + 0.5 * df
event.duration = duration
event.bandwidth = df
event.chisq_dof = 2 * duration * df
event.snr = math.sqrt(dof_tiles[i, j] / event.chisq_dof -
1)
# FIXME: Magic number 0.62 should be determine empircally
event.confidence = -lal.LogChisqCCDF(
event.snr * 0.62, event.chisq_dof * 0.62)
event.amplitude = None
event.process_id = None
event.event_id = event_list.get_next_id()
event_list.append(event)
for event in event_list[::-1]:
if event.amplitude != None:
continue
etime_min_idx = float(event.get_start()) - float(
fs_data.epoch)
etime_min_idx = int(etime_min_idx / tmp_ts_data.delta_t)
etime_max_idx = float(event.get_start()) - float(
fs_data.epoch) + event.duration
etime_max_idx = int(etime_max_idx / tmp_ts_data.delta_t)
# (band / 2) to account for sin^2 wings from finest filters
flow_idx = int((event.central_freq - event.bandwidth / 2 -
(df / 2) - fmin) / df)
fhigh_idx = int((event.central_freq + event.bandwidth / 2 +
(df / 2) - fmin) / df)
# TODO: Check that the undersampling rate is always commensurate
# with the indexing: that is to say that
# mod(etime_min_idx, us_rate) == 0 always
z_j_b = tf_map[flow_idx:fhigh_idx,
etime_min_idx:etime_max_idx:us_rate]
event.amplitude = 0
print "|------ Total number of events: %d" % len(event_list)
t_idx_min += int(seg_len * (1 - window_fraction))
t_idx_max += int(seg_len * (1 - window_fraction))
setname = "MagneticFields"
__program__ = 'pyburst_excesspower'
start_time = LIGOTimeGPS(int(ts_data.start_time))
end_time = LIGOTimeGPS(int(ts_data.end_time))
inseg = segment(start_time, end_time)
xmldoc = ligolw.Document()
xmldoc.appendChild(ligolw.LIGO_LW())
ifo = 'H1' #channel_name.split(":")[0]
straindict = psd.insert_psd_option_group.__dict__
proc_row = register_to_xmldoc(xmldoc,
__program__,
straindict,
ifos=[ifo],
version=git_version.id,
cvs_repository=git_version.branch,
cvs_entry_time=git_version.date)
dt_stride = psd_segment_length
sample_rate = ts_data.sample_rate
# Amount to overlap successive blocks so as not to lose data
window_overlap_samples = window_fraction * sample_rate
outseg = inseg.contract(window_fraction * dt_stride / 2)
# With a given dt_stride, we cannot process the remainder of this data
remainder = math.fmod(abs(outseg), dt_stride * (1 - window_fraction))
# ...so make an accounting of it
outseg = segment(outseg[0], outseg[1] - remainder)
ss = append_search_summary(xmldoc,
proc_row,
ifos=(station, ),
inseg=inseg,
outseg=outseg)
for sb in event_list:
sb.process_id = proc_row.process_id
sb.search = proc_row.program
sb.ifo, sb.channel = station, setname
xmldoc.childNodes[0].appendChild(event_list)
fname = 'excesspower.xml.gz'
utils.write_filename(xmldoc, fname, gz=fname.endswith("gz"))
def add_signal_to_noise(self):
"""
Sum the noise and the signal to get the 'measured' strain in the
detector
"""
# noise
noise = lal.CreateREAL8TimeSeries(
'blah', self.epoch, 0, self.td_noise.delta_t, lal.StrainUnit,
int(self.td_noise.duration / self.td_noise.delta_t))
noise.data.data = self.td_noise.data
# signal
signal = lal.CreateREAL8TimeSeries(
'blah', self.ext_params.geocent_peak_time, 0,
self.td_signal.delta_t, lal.StrainUnit,
int(self.td_signal.duration / self.td_signal.delta_t))
signal.data.data = self.td_signal.data
win = lal.CreateTukeyREAL8Window(len(signal.data.data), 0.1)
win.data.data[len(signal.data.data):] = 1.0
#signal.data.data *= win.data.data
# --- Scale to a target snr
print '---'
if self.target_snr is not None:
tmp_sig = pycbc.types.TimeSeries(signal.data.data,
delta_t=self.td_signal.delta_t)
current_snr = pycbc.filter.sigma(tmp_sig,
psd=self.psd,
low_frequency_cutoff=self.f_low,
high_frequency_cutoff=0.5 /
self.delta_t)
signal.data.data *= self.target_snr / current_snr
# ----
# sum
noise_plus_signal = lal.AddREAL8TimeSeries(noise, signal)
self.td_response = \
pycbc.types.timeseries.TimeSeries(\
initial_array=np.copy(noise_plus_signal.data.data),
delta_t=noise_plus_signal.deltaT,
epoch=noise_plus_signal.epoch)
# Finally, zero-pad the signal vector to have the same length as the actual data
# vector
no_noise = lal.CreateREAL8TimeSeries(
'blah', self.epoch, 0, self.td_noise.delta_t, lal.StrainUnit,
int(self.td_noise.duration / self.td_noise.delta_t))
no_noise.data.data = np.zeros(\
int(self.td_noise.duration / self.td_noise.delta_t))
signal = lal.AddREAL8TimeSeries(no_noise, signal)
self.td_signal = \
pycbc.types.timeseries.TimeSeries(initial_array=np.copy(signal.data.data),
delta_t=signal.deltaT, epoch=noise_plus_signal.epoch)
del noise, signal, noise_plus_signal
(freqaxis, low_cat, high_cat, shift_cat, original_cat, fpeaks, low_sigmas, high_sigmas) = pmns_pca_utils.build_catalogues(waveform_names, fshift_center) delta_f = np.diff(freqaxis)[0] # Convert to magnitude/phase full_mag, full_phase = pmns_pca_utils.complex_to_polar(original_cat) shift_mag, shift_phase = pmns_pca_utils.complex_to_polar(shift_cat) low_mag, low_phase = pmns_pca_utils.complex_to_polar(low_cat) high_mag, high_phase = pmns_pca_utils.complex_to_polar(high_cat) waveform = pmns_utils.Waveform(waveform_names[1]) waveform.reproject_waveform() # Window peakidx = np.argmax(abs(waveform.hplus.data)) win = lal.CreateTukeyREAL8Window(len(waveform.hplus), 0.25) waveform.hplus.data *= win.data.data wavdata = np.zeros(16384) wavdata[:len(waveform.hplus.data)] = np.copy(waveform.hplus.data) waveform_TD = pycbc.types.TimeSeries(wavdata, delta_t=waveform.hplus.delta_t) waveform_FD = waveform_TD.to_frequencyseries() mag = abs(waveform_FD.data) phase = np.unwrap(np.angle(waveform_FD.data)) # ******** # # Plotting # # ******** # imageformats = ['png', 'eps', 'pdf']
def movingaverage(interval, window_size):
window = lal.CreateTukeyREAL8Window(window_size, 0.5).data.data
return numpy.convolve(interval, window, 'same')
def tukeywindow(data, samps=200.):
assert (len(data) >= 2 * samps
) # make sure that the user is requesting something sane
tp = float(samps) / len(data)
return lal.CreateTukeyREAL8Window(len(data), tp).data.data
def excess_power(
ts_data, # Time series from magnetic field data
band=None, # Channel bandwidth
channel_name='channel-name', # Channel name
fmin=0, # Lowest frequency of the filter bank.
fmax=None, # Highest frequency of the filter bank.
impulse=False, # Impulse response
make_plot=True, # Condition to produce plots
max_duration=None, # Maximum duration of the tile
nchans=256, # Total number of channels
psd_estimation='median-mean', # Average method
psd_segment_length=60, # Length of each segment in seconds
psd_segment_stride=30, # Separation between 2 consecutive segments in seconds
station='station-name', # Station name
tile_fap=1e-7, # Tile false alarm probability threshold in Gaussian noise.
verbose=True, # Print details
window_fraction=0, # Withening window fraction
wtype='tukey'): # Whitening type, can tukey or hann
'''
Perform excess-power search analysis on magnetic field data.
This method will produce a bunch of time-frequency plots for every
tile duration and bandwidth analysed as well as a XML file identifying
all the triggers found in the selected data within the user-defined
time range.
Parameters
----------
ts_data : TimeSeries
Time Series from magnetic field data
psd_segment_length : float
Length of each segment in seconds
psd_segment_stride : float
Separation between 2 consecutive segments in seconds
psd_estimation : string
Average method
window_fraction : float
Withening window fraction
tile_fap : float
Tile false alarm probability threshold in Gaussian noise.
nchans : int
Total number of channels
band : float
Channel bandwidth
fmin : float
Lowest frequency of the filter bank.
fmax : float
Highest frequency of the filter bank
Examples
--------
The program can be ran as an executable by using the ``excesspower`` command
line as follows::
excesspower --station "mainz01" \\
--start-time "2017-04-15-17-1" \\
--end-time "2017-04-15-18" \\
--rep "/Users/vincent/ASTRO/data/GNOME/GNOMEDrive/gnome/serverdata/" \\
--resample 512 \\
--verbose
'''
# Determine sampling rate based on extracted time series
sample_rate = ts_data.sample_rate
# Check if tile maximum frequency is not defined
if fmax is None or fmax > sample_rate / 2.:
# Set the tile maximum frequency equal to the Nyquist frequency
# (i.e. half the sampling rate)
fmax = sample_rate / 2.0
# Check whether or not tile bandwidth and channel are defined
if band is None and nchans is None:
# Exit program with error message
exit("Either bandwidth or number of channels must be specified...")
else:
# Check if tile maximum frequency larger than its minimum frequency
assert fmax >= fmin
# Define spectral band of data
data_band = fmax - fmin
# Check whether tile bandwidth or channel is defined
if band is not None:
# Define number of possible filter bands
nchans = int(data_band / band)
elif nchans is not None:
# Define filter bandwidth
band = data_band / nchans
nchans -= 1
# Check if number of channels is superior than unity
assert nchans > 1
# Print segment information
if verbose: print '|- Estimating PSD from segments of',
if verbose:
print '%.2f s, with %.2f s stride...' % (psd_segment_length,
psd_segment_stride)
# Convert time series as array of float
data = ts_data.astype(numpy.float64)
# Define segment length for PSD estimation in sample unit
seg_len = int(psd_segment_length * sample_rate)
# Define separation between consecutive segments in sample unit
seg_stride = int(psd_segment_stride * sample_rate)
# Minimum frequency of detectable signal in a segment
delta_f = 1. / psd_segment_length
# Calculate PSD length counting the zero frequency element
fd_len = fmax / delta_f + 1
# Calculate the overall PSD from individual PSD segments
if impulse:
# Produce flat data
flat_data = numpy.ones(int(fd_len)) * 2. / fd_len
# Create PSD frequency series
fd_psd = types.FrequencySeries(flat_data, 1. / psd_segment_length,
ts_data.start_time)
else:
# Create overall PSD using Welch's method
fd_psd = psd.welch(data,
avg_method=psd_estimation,
seg_len=seg_len,
seg_stride=seg_stride)
if make_plot:
# Plot the power spectral density
plot_spectrum(fd_psd)
# We need this for the SWIG functions
lal_psd = fd_psd.lal()
# Create whitening window
if verbose: print "|- Whitening window and spectral correlation..."
if wtype == 'hann': window = lal.CreateHannREAL8Window(seg_len)
elif wtype == 'tukey':
window = lal.CreateTukeyREAL8Window(seg_len, window_fraction)
else:
raise ValueError("Can't handle window type %s" % wtype)
# Create FFT plan
fft_plan = lal.CreateForwardREAL8FFTPlan(len(window.data.data), 1)
# Perform two point spectral correlation
spec_corr = lal.REAL8WindowTwoPointSpectralCorrelation(window, fft_plan)
# Determine length of individual filters
filter_length = int(2 * band / fd_psd.delta_f) + 1
# Initialise filter bank
if verbose:
print "|- Create bank of %i filters of %i Hz bandwidth..." % (
nchans, filter_length)
# Initialise array to store filter's frequency series and metadata
lal_filters = []
# Initialise array to store filter's time series
fdb = []
# Loop over the channels
for i in range(nchans):
# Define central position of the filter
freq = fmin + band / 2 + i * band
# Create excess power filter
lal_filter = lalburst.CreateExcessPowerFilter(freq, band, lal_psd,
spec_corr)
# Testing spectral correlation on filter
#print lalburst.ExcessPowerFilterInnerProduct(lal_filter, lal_filter, spec_corr, None)
# Append entire filter structure
lal_filters.append(lal_filter)
# Append filter's spectrum
fdb.append(FrequencySeries.from_lal(lal_filter))
#print fdb[0].frequencies
#print fdb[0]
if make_plot:
# Plot filter bank
plot_bank(fdb)
# Convert filter bank from frequency to time domain
if verbose:
print "|- Convert all the frequency domain to the time domain..."
tdb = []
# Loop for each filter's spectrum
for fdt in fdb:
zero_padded = numpy.zeros(int((fdt.f0 / fdt.df).value) + len(fdt))
st = int((fdt.f0 / fdt.df).value)
zero_padded[st:st + len(fdt)] = numpy.real_if_close(fdt.value)
n_freq = int(sample_rate / 2 / fdt.df.value) * 2
tdt = numpy.fft.irfft(zero_padded, n_freq) * math.sqrt(sample_rate)
tdt = numpy.roll(tdt, len(tdt) / 2)
tdt = TimeSeries(tdt,
name="",
epoch=fdt.epoch,
sample_rate=sample_rate)
tdb.append(tdt)
# Plot time series filter
plot_filters(tdb, fmin, band)
# Computer whitened inner products of input filters with themselves
#white_filter_ip = numpy.array([lalburst.ExcessPowerFilterInnerProduct(f, f, spec_corr, None) for f in lal_filters])
# Computer unwhitened inner products of input filters with themselves
#unwhite_filter_ip = numpy.array([lalburst.ExcessPowerFilterInnerProduct(f, f, spec_corr, lal_psd) for f in lal_filters])
# Computer whitened filter inner products between input adjacent filters
#white_ss_ip = numpy.array([lalburst.ExcessPowerFilterInnerProduct(f1, f2, spec_corr, None) for f1, f2 in zip(lal_filters[:-1], lal_filters[1:])])
# Computer unwhitened filter inner products between input adjacent filters
#unwhite_ss_ip = numpy.array([lalburst.ExcessPowerFilterInnerProduct(f1, f2, spec_corr, lal_psd) for f1, f2 in zip(lal_filters[:-1], lal_filters[1:])])
# Check filter's bandwidth is equal to user defined channel bandwidth
min_band = (len(lal_filters[0].data.data) - 1) * lal_filters[0].deltaF / 2
assert min_band == band
# Create an event list where all the triggers will be stored
event_list = lsctables.New(lsctables.SnglBurstTable, [
'start_time', 'start_time_ns', 'peak_time', 'peak_time_ns', 'duration',
'bandwidth', 'central_freq', 'chisq_dof', 'confidence', 'snr',
'amplitude', 'channel', 'ifo', 'process_id', 'event_id', 'search',
'stop_time', 'stop_time_ns'
])
# Create repositories to save TF and time series plots
os.system('mkdir -p segments/time-frequency')
os.system('mkdir -p segments/time-series')
# Define time edges
t_idx_min, t_idx_max = 0, seg_len
# Loop over each segment
while t_idx_max <= len(ts_data):
# Define first and last timestamps of the block
start_time = ts_data.start_time + t_idx_min / float(
ts_data.sample_rate)
end_time = ts_data.start_time + t_idx_max / float(ts_data.sample_rate)
if verbose:
print "\n|- Analyzing block %i to %i (%.2f percent)" % (
start_time, end_time, 100 * float(t_idx_max) / len(ts_data))
# Debug for impulse response
if impulse:
for i in range(t_idx_min, t_idx_max):
ts_data[i] = 1000. if i == (t_idx_max + t_idx_min) / 2 else 0.
# Model a withen time series for the block
tmp_ts_data = types.TimeSeries(ts_data[t_idx_min:t_idx_max] *
window.data.data,
delta_t=1. / ts_data.sample_rate,
epoch=start_time)
# Save time series in relevant repository
os.system('mkdir -p segments/%i-%i' % (start_time, end_time))
if make_plot:
# Plot time series
plot_ts(tmp_ts_data,
fname='segments/time-series/%i-%i.png' %
(start_time, end_time))
# Convert times series to frequency series
fs_data = tmp_ts_data.to_frequencyseries()
if verbose:
print "|- Frequency series data has variance: %s" % fs_data.data.std(
)**2
# Whitening (FIXME: Whiten the filters, not the data)
fs_data.data /= numpy.sqrt(fd_psd) / numpy.sqrt(2 * fd_psd.delta_f)
if verbose:
print "|- Whitened frequency series data has variance: %s" % fs_data.data.std(
)**2
if verbose: print "|- Create time-frequency plane for current block"
# Return the complex snr, along with its associated normalization of the template,
# matched filtered against the data
#filter.matched_filter_core(types.FrequencySeries(tmp_filter_bank,delta_f=fd_psd.delta_f),
# fs_data,h_norm=1,psd=fd_psd,low_frequency_cutoff=lal_filters[0].f0,
# high_frequency_cutoff=lal_filters[0].f0+2*band)
if verbose: print "|- Filtering all %d channels...\n" % nchans,
# Initialise 2D zero array
tmp_filter_bank = numpy.zeros(len(fd_psd), dtype=numpy.complex128)
# Initialise 2D zero array for time-frequency map
tf_map = numpy.zeros((nchans, seg_len), dtype=numpy.complex128)
# Loop over all the channels
for i in range(nchans):
# Reset filter bank series
tmp_filter_bank *= 0.0
# Index of starting frequency
f1 = int(lal_filters[i].f0 / fd_psd.delta_f)
# Index of last frequency bin
f2 = int((lal_filters[i].f0 + 2 * band) / fd_psd.delta_f) + 1
# (FIXME: Why is there a factor of 2 here?)
tmp_filter_bank[f1:f2] = lal_filters[i].data.data * 2
# Define the template to filter the frequency series with
template = types.FrequencySeries(tmp_filter_bank,
delta_f=fd_psd.delta_f,
copy=False)
# Create filtered series
filtered_series = filter.matched_filter_core(
template,
fs_data,
h_norm=None,
psd=None,
low_frequency_cutoff=lal_filters[i].f0,
high_frequency_cutoff=lal_filters[i].f0 + 2 * band)
# Include filtered series in the map
tf_map[i, :] = filtered_series[0].numpy()
if make_plot:
# Plot spectrogram
plot_spectrogram(numpy.abs(tf_map).T,
dt=tmp_ts_data.delta_t,
df=band,
ymax=ts_data.sample_rate / 2.,
t0=start_time,
t1=end_time,
fname='segments/time-frequency/%i-%i.png' %
(start_time, end_time))
plot_tiles_ts(numpy.abs(tf_map),
2,
1,
sample_rate=ts_data.sample_rate,
t0=start_time,
t1=end_time,
fname='segments/%i-%i/ts.png' %
(start_time, end_time))
#plot_tiles_tf(numpy.abs(tf_map),2,1,ymax=ts_data.sample_rate/2,
# sample_rate=ts_data.sample_rate,t0=start_time,t1=end_time,
# fname='segments/%i-%i/tf.png'%(start_time,end_time))
# Loop through powers of 2 up to number of channels
for nc_sum in range(0, int(math.log(nchans, 2)))[::-1]:
# Calculate total number of summed channels
nc_sum = 2**nc_sum
if verbose:
print "\n\t|- Contructing tiles containing %d narrow band channels" % nc_sum
# Compute full bandwidth of virtual channel
df = band * nc_sum
# Compute minimal signal's duration in virtual channel
dt = 1.0 / (2 * df)
# Compute under sampling rate
us_rate = int(round(dt / ts_data.delta_t))
if verbose:
print "\t|- Undersampling rate for this level: %f" % (
ts_data.sample_rate / us_rate)
if verbose: print "\t|- Calculating tiles..."
# Clip the boundaries to remove window corruption
clip_samples = int(psd_segment_length * window_fraction *
ts_data.sample_rate / 2)
# Undersample narrow band channel's time series
# Apply clipping condition because [0:-0] does not give the full array
tf_map_temp = tf_map[:,clip_samples:-clip_samples:us_rate] \
if clip_samples > 0 else tf_map[:,::us_rate]
# Initialise final tile time-frequency map
tiles = numpy.zeros(((nchans + 1) / nc_sum, tf_map_temp.shape[1]))
# Loop over tile index
for i in xrange(len(tiles)):
# Sum all inner narrow band channels
ts_tile = numpy.absolute(tf_map_temp[nc_sum * i:nc_sum *
(i + 1)].sum(axis=0))
# Define index of last narrow band channel for given tile
n = (i + 1) * nc_sum - 1
n = n - 1 if n == len(lal_filters) else n
# Computer withened inner products of each input filter with itself
mu_sq = nc_sum * lalburst.ExcessPowerFilterInnerProduct(
lal_filters[n], lal_filters[n], spec_corr, None)
#kmax = nc_sum-1 if n==len(lal_filters) else nc_sum-2
# Loop over the inner narrow band channels
for k in xrange(0, nc_sum - 1):
# Computer whitened filter inner products between input adjacent filters
mu_sq += 2 * lalburst.ExcessPowerFilterInnerProduct(
lal_filters[n - k], lal_filters[n - 1 - k], spec_corr,
None)
# Normalise tile's time series
tiles[i] = ts_tile.real**2 / mu_sq
if verbose: print "\t|- TF-plane is %dx%s samples" % tiles.shape
if verbose:
print "\t|- Tile energy mean %f, var %f" % (numpy.mean(tiles),
numpy.var(tiles))
# Define maximum number of degrees of freedom and check it larger or equal to 2
max_dof = 32 if max_duration == None else int(max_duration / dt)
assert max_dof >= 2
# Loop through multiple degrees of freedom
for j in [2**l for l in xrange(0, int(math.log(max_dof, 2)))]:
# Duration is fixed by the NDOF and bandwidth
duration = j * dt
if verbose: print "\n\t\t|- Summing DOF = %d ..." % (2 * j)
if verbose:
print "\t\t|- Explore signal duration of %f s..." % duration
# Construct filter
sum_filter = numpy.array([1, 0] * (j - 1) + [1])
# Calculate length of filtered time series
tlen = tiles.shape[1] - sum_filter.shape[0] + 1
# Initialise filtered time series array
dof_tiles = numpy.zeros((tiles.shape[0], tlen))
# Loop over tiles
for f in range(tiles.shape[0]):
# Sum and drop correlate tiles
dof_tiles[f] = fftconvolve(tiles[f], sum_filter, 'valid')
if verbose:
print "\t\t|- Summed tile energy mean: %f" % (
numpy.mean(dof_tiles))
if verbose:
print "\t\t|- Variance tile energy: %f" % (
numpy.var(dof_tiles))
if make_plot:
plot_spectrogram(
dof_tiles.T,
dt,
df,
ymax=ts_data.sample_rate / 2,
t0=start_time,
t1=end_time,
fname='segments/%i-%i/%02ichans_%02idof.png' %
(start_time, end_time, nc_sum, 2 * j))
plot_tiles_ts(
dof_tiles,
2 * j,
df,
sample_rate=ts_data.sample_rate / us_rate,
t0=start_time,
t1=end_time,
fname='segments/%i-%i/%02ichans_%02idof_ts.png' %
(start_time, end_time, nc_sum, 2 * j))
plot_tiles_tf(
dof_tiles,
2 * j,
df,
ymax=ts_data.sample_rate / 2,
sample_rate=ts_data.sample_rate / us_rate,
t0=start_time,
t1=end_time,
fname='segments/%i-%i/%02ichans_%02idof_tf.png' %
(start_time, end_time, nc_sum, 2 * j))
threshold = scipy.stats.chi2.isf(tile_fap, j)
if verbose:
print "\t\t|- Threshold for this level: %f" % threshold
spant, spanf = dof_tiles.shape[1] * dt, dof_tiles.shape[0] * df
if verbose:
print "\t\t|- Processing %.2fx%.2f time-frequency map." % (
spant, spanf)
# Since we clip the data, the start time needs to be adjusted accordingly
window_offset_epoch = fs_data.epoch + psd_segment_length * window_fraction / 2
window_offset_epoch = LIGOTimeGPS(float(window_offset_epoch))
for i, j in zip(*numpy.where(dof_tiles > threshold)):
event = event_list.RowType()
# The points are summed forward in time and thus a `summed point' is the
# sum of the previous N points. If this point is above threshold, it
# corresponds to a tile which spans the previous N points. However, the
# 0th point (due to the convolution specifier 'valid') is actually
# already a duration from the start time. All of this means, the +
# duration and the - duration cancels, and the tile 'start' is, by
# definition, the start of the time frequency map if j = 0
# FIXME: I think this needs a + dt/2 to center the tile properly
event.set_start(window_offset_epoch + float(j * dt))
event.set_stop(window_offset_epoch + float(j * dt) +
duration)
event.set_peak(event.get_start() + duration / 2)
event.central_freq = lal_filters[
0].f0 + band / 2 + i * df + 0.5 * df
event.duration = duration
event.bandwidth = df
event.chisq_dof = 2 * duration * df
event.snr = math.sqrt(dof_tiles[i, j] / event.chisq_dof -
1)
# FIXME: Magic number 0.62 should be determine empircally
event.confidence = -lal.LogChisqCCDF(
event.snr * 0.62, event.chisq_dof * 0.62)
event.amplitude = None
event.process_id = None
event.event_id = event_list.get_next_id()
event_list.append(event)
for event in event_list[::-1]:
if event.amplitude != None:
continue
etime_min_idx = float(event.get_start()) - float(
fs_data.epoch)
etime_min_idx = int(etime_min_idx / tmp_ts_data.delta_t)
etime_max_idx = float(event.get_start()) - float(
fs_data.epoch) + event.duration
etime_max_idx = int(etime_max_idx / tmp_ts_data.delta_t)
# (band / 2) to account for sin^2 wings from finest filters
flow_idx = int((event.central_freq - event.bandwidth / 2 -
(df / 2) - fmin) / df)
fhigh_idx = int((event.central_freq + event.bandwidth / 2 +
(df / 2) - fmin) / df)
# TODO: Check that the undersampling rate is always commensurate
# with the indexing: that is to say that
# mod(etime_min_idx, us_rate) == 0 always
z_j_b = tf_map[flow_idx:fhigh_idx,
etime_min_idx:etime_max_idx:us_rate]
# FIXME: Deal with negative hrss^2 -- e.g. remove the event
try:
event.amplitude = measure_hrss(
z_j_b, unwhite_filter_ip[flow_idx:fhigh_idx],
unwhite_ss_ip[flow_idx:fhigh_idx - 1],
white_ss_ip[flow_idx:fhigh_idx - 1],
fd_psd.delta_f, tmp_ts_data.delta_t,
len(lal_filters[0].data.data), event.chisq_dof)
except ValueError:
event.amplitude = 0
if verbose:
print "\t\t|- Total number of events: %d" % len(event_list)
t_idx_min += int(seg_len * (1 - window_fraction))
t_idx_max += int(seg_len * (1 - window_fraction))
setname = "MagneticFields"
__program__ = 'pyburst_excesspower_gnome'
start_time = LIGOTimeGPS(int(ts_data.start_time))
end_time = LIGOTimeGPS(int(ts_data.end_time))
inseg = segment(start_time, end_time)
xmldoc = ligolw.Document()
xmldoc.appendChild(ligolw.LIGO_LW())
ifo = channel_name.split(":")[0]
straindict = psd.insert_psd_option_group.__dict__
proc_row = register_to_xmldoc(xmldoc,
__program__,
straindict,
ifos=[ifo],
version=git_version.id,
cvs_repository=git_version.branch,
cvs_entry_time=git_version.date)
dt_stride = psd_segment_length
sample_rate = ts_data.sample_rate
# Amount to overlap successive blocks so as not to lose data
window_overlap_samples = window_fraction * sample_rate
outseg = inseg.contract(window_fraction * dt_stride / 2)
# With a given dt_stride, we cannot process the remainder of this data
remainder = math.fmod(abs(outseg), dt_stride * (1 - window_fraction))
# ...so make an accounting of it
outseg = segment(outseg[0], outseg[1] - remainder)
ss = append_search_summary(xmldoc,
proc_row,
ifos=(station, ),
inseg=inseg,
outseg=outseg)
for sb in event_list:
sb.process_id = proc_row.process_id
sb.search = proc_row.program
sb.ifo, sb.channel = station, setname
xmldoc.childNodes[0].appendChild(event_list)
ifostr = ifo if isinstance(ifo, str) else "".join(ifo)
st_rnd, end_rnd = int(math.floor(inseg[0])), int(math.ceil(inseg[1]))
dur = end_rnd - st_rnd
fname = "%s-excesspower-%d-%d.xml.gz" % (ifostr, st_rnd, dur)
utils.write_filename(xmldoc, fname, gz=fname.endswith("gz"))
plot_triggers(fname)
