Ejemplo n.º 1
0
    def combined_time_volume(self, allsegments, allranges):
        try:
            combined_range = TimeSeries(numpy.zeros(allranges[0].size),
                                        xindex=allranges[0].times,
                                        unit='Mpc')
        except IndexError:
            combined_range = TimeSeries(numpy.zeros(allranges[0].size),
                                        unit='Mpc',
                                        x0=allranges[0].x0,
                                        dx=allranges[0].dx)

        # get coincident observing segments
        pairs = list(combinations(allsegments, 2))
        coincident = SegmentList()
        for pair in pairs:
            coincident.extend(pair[0] & pair[1])
        coincident = coincident.coalesce()

        # get effective network range
        values = [r.value for r in allranges]
        values = [min(nlargest(2, x)) for x in zip(*values)]
        size = min([r.size for r in allranges])
        combined_range[:size] = values * combined_range.unit

        # compute time-volume
        return self.calculate_time_volume(coincident, combined_range)
Ejemplo n.º 2
0
def cache_overlaps(*caches):
    """Find segments of overlap in the given cache sets
    """
    cache = [e for c in caches for e in c]
    cache.sort(key=lambda e: file_segment(e)[0])
    overlap = SegmentList()
    segments = SegmentList()
    for e in cache:
        seg = file_segment(e)
        ol = SegmentList([seg]) & segments
        if abs(ol):
            overlap.extend(ol)
        segments.append(seg)
    return overlap
Ejemplo n.º 3
0
def cache_overlaps(*caches):
    """Find segments of overlap in the given cache sets
    """
    cache = [e for c in caches for e in c]
    cache.sort(key=lambda e: file_segment(e)[0])
    overlap = SegmentList()
    segments = SegmentList()
    for e in cache:
        seg = file_segment(e)
        ol = SegmentList([seg]) & segments
        if abs(ol):
            overlap.extend(ol)
        segments.append(seg)
    return overlap
Ejemplo n.º 4
0
Archivo: range.py Proyecto: gwpy/gwsumm
    def combined_time_volume(self, allsegments, allranges):
        try:
            combined_range = TimeSeries(numpy.zeros(allranges[0].size),
                                        xindex=allranges[0].times, unit='Mpc')
        except IndexError:
            combined_range = TimeSeries(
                numpy.zeros(allranges[0].size), unit='Mpc',
                x0=allranges[0].x0, dx=allranges[0].dx)

        # get coincident observing segments
        pairs = list(combinations(allsegments, 2))
        coincident = SegmentList()
        for pair in pairs:
            coincident.extend(pair[0] & pair[1])
        coincident = coincident.coalesce()

        # get effective network range
        values = [r.value for r in allranges]
        values = [min(nlargest(2, x)) for x in zip(*values)]
        size = min([r.size for r in allranges])
        combined_range[:size] = values * combined_range.unit

        # compute time-volume
        return self.calculate_time_volume(coincident, combined_range)
Ejemplo n.º 5
0
def main(args=None):
    """Run the primary scattering command-line tool
    """
    parser = create_parser()
    args = parser.parse_args(args=args)

    # set up logger
    logger = cli.logger(
        name=PROG.split('python -m ').pop(),
        level='DEBUG' if args.verbose else 'INFO',
    )

    # useful variables
    fthresh = (
        int(args.frequency_threshold) if args.frequency_threshold.is_integer()
        else args.frequency_threshold)
    multiplier = args.multiplier_for_threshold
    tstr = str(fthresh).replace('.', '_')
    gpsstr = '%s-%s' % (int(args.gpsstart), int(args.gpsend - args.gpsstart))
    args.optic = args.optic or list(OPTIC_MOTION_CHANNELS.keys())

    # go to working directory
    indir = os.getcwd()
    if not os.path.isdir(args.output_dir):
        os.makedirs(args.output_dir)
    os.chdir(args.output_dir)

    # set up output files
    summfile = '{}-SCATTERING_SUMMARY-{}.csv'.format(
        args.ifo, gpsstr)
    segfile = '{}-SCATTERING_SEGMENTS_{}_HZ-{}.h5'.format(
        args.ifo, tstr, gpsstr)

    # log start of process
    logger.info('{} Scattering {}-{}'.format(
        args.ifo, int(args.gpsstart), int(args.gpsend)))

    # -- get state segments -----------

    span = Segment(args.gpsstart, args.gpsend)

    # get segments
    if args.state_flag is not None:
        state = DataQualityFlag.query(
            args.state_flag, int(args.gpsstart), int(args.gpsend),
            url=DEFAULT_SEGMENT_SERVER,
        ).coalesce()
        statea = []
        padding = args.segment_start_pad + args.segment_end_pad
        for i, seg in enumerate(state.active):
            if abs(seg) > padding:
                statea.append(Segment(
                    seg[0] + args.segment_start_pad,
                    seg[1] - args.segment_end_pad,
                ))
            else:
                logger.debug(
                    "Segment length {} shorter than padding length {}, "
                    "skipping segment {}-{}".format(abs(seg), padding, *seg),
                )
        statea = SegmentList(statea)
        logger.debug("Downloaded %d segments for %s"
                     % (len(statea), args.state_flag))
    else:
        statea = SegmentList([span])
    livetime = float(abs(statea))
    logger.debug("Processing %.2f s of livetime" % livetime)

    # -- load h(t) --------------------

    args.main_channel = args.main_channel.format(IFO=args.ifo)
    logger.debug("Loading Omicron triggers for %s" % args.main_channel)

    if args.gpsstart >= 1230336018:  # Jan 1 2019
        ext = "h5"
        names = ["time", "frequency", "snr"]
        read_kw = {
            "columns": names,
            "selection": [
                "{0} < frequency < {1}".format(
                    args.fmin, multiplier * fthresh),
                ("time", in_segmentlist, statea),
            ],
            "format": "hdf5",
            "path": "triggers",
        }
    else:
        ext = "xml.gz"
        names = ['peak', 'peak_frequency', 'snr']
        read_kw = {
            "columns": names,
            "selection": [
                "{0} < peak_frequency < {1}".format(
                    args.fmin, multiplier * fthresh),
                ('peak', in_segmentlist, statea),
            ],
            "format": 'ligolw',
            "tablename": "sngl_burst",
        }

    fullcache = []
    for seg in statea:
        cache = gwtrigfind.find_trigger_files(
            args.main_channel, 'omicron', seg[0], seg[1], ext=ext,
        )
        if len(cache) == 0:
            warnings.warn(
                "No Omicron triggers found for %s in segment [%d .. %d)"
                % (args.main_channel, seg[0], seg[1]),
            )
            continue
        fullcache.extend(cache)

    # read triggers
    if fullcache:
        trigs = EventTable.read(fullcache, nproc=args.nproc, **read_kw)
    else:  # no files (no livetime?)
        trigs = EventTable(names=names)

    highsnrtrigs = trigs[trigs['snr'] >= 8]
    logger.debug("%d read" % len(trigs))

    # -- prepare HTML -----------------

    links = [
        '%d-%d' % (int(args.gpsstart), int(args.gpsend)),
        ('Parameters', '#parameters'),
        ('Segments', (
            ('State flag', '#state-flag'),
            ('Optical sensors', '#osems'),
            ('Transmons', '#transmons'),
        )),
    ]
    if args.omega_scans:
        links.append(('Scans', '#omega-scans'))
    (brand, class_) = htmlio.get_brand(args.ifo, 'Scattering', args.gpsstart)
    navbar = htmlio.navbar(links, class_=class_, brand=brand)
    page = htmlio.new_bootstrap_page(
        title='%s Scattering | %d-%d' % (
            args.ifo, int(args.gpsstart), int(args.gpsend)),
        navbar=navbar)
    page.div(class_='pb-2 mt-3 mb-2 border-bottom')
    page.h1('%s Scattering: %d-%d'
            % (args.ifo, int(args.gpsstart), int(args.gpsend)))
    page.div.close()  # pb-2 mt-3 mb-2 border-bottom
    page.h2('Parameters', class_='mt-4 mb-4', id_='parameters')
    page.div(class_='row')
    page.div(class_='col-md-9 col-sm-12')
    page.add(htmlio.parameter_table(
        start=int(args.gpsstart), end=int(args.gpsend), flag=args.state_flag))
    page.div.close()  # col-md-9 col-sm-12

    # link to summary files
    page.div(class_='col-md-3 col-sm-12')
    page.add(htmlio.download_btn(
        [('Segments (HDF)', segfile),
         ('Triggers (CSV)', summfile)],
        btnclass='btn btn-%s dropdown-toggle' % args.ifo.lower(),
    ))
    page.div.close()  # col-md-3 col-sm-12
    page.div.close()  # row

    # command-line
    page.h5('Command-line:')
    page.add(htmlio.get_command_line(about=False, prog=PROG))

    # section header
    page.h2('Segments', class_='mt-4', id_='segments')

    if statea:  # contextual information
        paper = markup.oneliner.a(
            'Accadia et al. (2010)', target='_blank', class_='alert-link',
            href='http://iopscience.iop.org/article/10.1088/0264-9381/27'
                 '/19/194011')
        msg = (
            "Segments marked \"optical sensors\" below show evidence of beam "
            "scattering between {0} and {1} Hz based on the velocity of optic "
            "motion, with fringe frequencies projected using equation (3) of "
            "{2}. Segments marked \"transmons\" are based on whitened, "
            "band-limited RMS trends of transmon sensors. In both cases, "
            "yellow panels denote weak evidence for scattering, while red "
            "panels denote strong evidence."
         ).format(args.fmin, multiplier * fthresh, str(paper))
        page.add(htmlio.alert(msg, context=args.ifo.lower()))
    else:  # null segments
        page.add(htmlio.alert('No active analysis segments were found',
                              context='warning', dismiss=False))

    # record state segments
    if args.state_flag is not None:
        page.h3('State flag', class_='mt-3', id_='state-flag')
        page.div(id_='accordion1')
        page.add(htmlio.write_flag_html(
            state, span, 'state', parent='accordion1', context='success',
            plotdir='', facecolor=(0.2, 0.8, 0.2), edgecolor='darkgreen',
            known={'facecolor': 'red', 'edgecolor': 'darkred', 'height': 0.4}))
        page.div.close()

    # -- find scattering evidence -----

    # read data for OSEMs and transmons
    osems = ['%s:%s' % (args.ifo, c) for optic in args.optic for
             c in OPTIC_MOTION_CHANNELS[optic]]
    transmons = ['%s:%s' % (args.ifo, c) for c in TRANSMON_CHANNELS]
    allchannels = osems + transmons

    logger.info("Reading all timeseries data")
    alldata = []
    n = len(statea)
    for i, seg in enumerate(statea):
        msg = "{0}/{1} {2}:".rjust(30).format(
            str(i + 1).rjust(len(str(n))),
            n,
            str(seg),
        ) if args.verbose else False
        alldata.append(
            get_data(allchannels, seg[0], seg[1],
                     frametype=args.frametype.format(IFO=args.ifo),
                     verbose=msg, nproc=args.nproc).resample(128))
    try:  # ensure that only available channels are analyzed
        osems = list(
            set(alldata[0].keys()) & set(alldata[-1].keys()) & set(osems))
        transmons = list(
            set(alldata[0].keys()) & set(alldata[-1].keys()) & set(transmons))
    except IndexError:
        osems = []
        transmons = []

    # initialize scattering segments
    scatter_segments = DataQualityDict()
    actives = SegmentList()

    # scattering based on OSEM velocity
    if statea:
        page.h3('Optical sensors (OSEMs)', class_='mt-3', id_='osems')
        page.div(id_='osems-group')
    logger.info('Searching for scatter based on OSEM velocity')

    for i, channel in enumerate(sorted(osems)):
        logger.info("-- Processing %s --" % channel)
        chanstr = re.sub('[:-]', '_', channel).replace('_', '-', 1)
        optic = channel.split('-')[1].split('_')[0]
        flag = '%s:DCH-%s_SCATTERING_GE_%s_HZ:1' % (args.ifo, optic, tstr)
        scatter_segments[channel] = DataQualityFlag(
            flag,
            isgood=False,
            description="Evidence for scattering above {0} Hz from {1} in "
                        "{2}".format(fthresh, optic, channel),
        )
        # set up plot(s)
        plot = Plot(figsize=[12, 12])
        axes = {}
        axes['position'] = plot.add_subplot(
            411, xscale='auto-gps', xlabel='')
        axes['fringef'] = plot.add_subplot(
            412, sharex=axes['position'], xlabel='')
        axes['triggers'] = plot.add_subplot(
            413, sharex=axes['position'], xlabel='')
        axes['segments'] = plot.add_subplot(
            414, projection='segments', sharex=axes['position'])
        plot.subplots_adjust(bottom=.07, top=.95)
        fringecolors = [None] * len(FREQUENCY_MULTIPLIERS)
        histdata = dict((x, numpy.ndarray((0,))) for
                        x in FREQUENCY_MULTIPLIERS)
        linecolor = None
        # loop over state segments and find scattering fringes
        for j, seg in enumerate(statea):
            logger.debug("Processing segment [%d .. %d)" % seg)
            ts = alldata[j][channel]
            # get raw data and plot
            line = axes['position'].plot(ts, color=linecolor)[0]
            linecolor = line.get_color()
            # get fringe frequency and plot
            fringef = get_fringe_frequency(ts, multiplier=1)
            for k, m in list(enumerate(FREQUENCY_MULTIPLIERS))[::-1]:
                fm = fringef * m
                line = axes['fringef'].plot(
                    fm, color=fringecolors[k],
                    label=(j == 0 and r'$f\times%d$' % m or None))[0]
                fringecolors[k] = line.get_color()
                histdata[m] = numpy.resize(
                    histdata[m], (histdata[m].size + fm.size,))
                histdata[m][-fm.size:] = fm.value
            # get segments and plot
            scatter = get_segments(
                fringef * multiplier,
                fthresh,
                name=flag,
                pad=args.segment_padding
            )
            axes['segments'].plot(
                scatter, facecolor='red', edgecolor='darkred',
                known={'alpha': 0.6, 'facecolor': 'lightgray',
                       'edgecolor': 'gray', 'height': 0.4},
                height=0.8, y=0, label=' ',
            )
            scatter_segments[channel] += scatter
            logger.debug(
                "    Found %d scattering segments" % (len(scatter.active)))
        logger.debug("Completed channel %s, found %d segments in total"
                     % (channel, len(scatter_segments[channel].active)))

        # calculate efficiency and deadtime of veto
        deadtime = abs(scatter_segments[channel].active)
        try:
            deadtimepc = deadtime / livetime * 100
        except ZeroDivisionError:
            deadtimepc = 0.
        logger.info("Deadtime: %.2f%% (%.2f/%ds)"
                    % (deadtimepc, deadtime, livetime))
        efficiency = in_segmentlist(highsnrtrigs[names[0]],
                                    scatter_segments[channel].active).sum()
        try:
            efficiencypc = efficiency / len(highsnrtrigs) * 100
        except ZeroDivisionError:
            efficiencypc = 0.
        logger.info("Efficiency (SNR>=8): %.2f%% (%d/%d)"
                    % (efficiencypc, efficiency, len(highsnrtrigs)))
        if deadtimepc == 0.:
            effdt = 0
        else:
            effdt = efficiencypc/deadtimepc
        logger.info("Efficiency/Deadtime: %.2f" % effdt)

        if abs(scatter_segments[channel].active):
            actives.extend(scatter_segments[channel].active)

        # finalize plot
        logger.debug("Plotting")
        name = texify(channel)
        axes['position'].set_title("Scattering evidence in %s" % name)
        axes['position'].set_xlabel('')
        axes['position'].set_ylabel(r'Position [$\mu$m]')
        axes['position'].text(
            0.01, 0.95, 'Optic position',
            transform=axes['position'].transAxes, va='top', ha='left',
            bbox={'edgecolor': 'none', 'facecolor': 'white', 'alpha': .5})
        axes['fringef'].plot(
            span, [fthresh, fthresh], 'k--')
        axes['fringef'].set_xlabel('')
        axes['fringef'].set_ylabel(r'Frequency [Hz]')
        axes['fringef'].yaxis.tick_right()
        axes['fringef'].yaxis.set_label_position("right")
        axes['fringef'].set_ylim(0, multiplier * fthresh)
        axes['fringef'].text(
            0.01, 0.95, 'Calculated fringe frequency',
            transform=axes['fringef'].transAxes, va='top', ha='left',
            bbox={'edgecolor': 'none', 'facecolor': 'white', 'alpha': .5})
        handles, labels = axes['fringef'].get_legend_handles_labels()
        axes['fringef'].legend(handles[::-1], labels[::-1], loc='upper right',
                               borderaxespad=0, bbox_to_anchor=(-0.01, 1.),
                               handlelength=1)

        axes['triggers'].scatter(
            trigs[names[0]],
            trigs[names[1]],
            c=trigs[names[2]],
            edgecolor='none',
        )
        name = texify(args.main_channel)
        axes['triggers'].text(
            0.01, 0.95,
            '%s event triggers (Omicron)' % name,
            transform=axes['triggers'].transAxes, va='top', ha='left',
            bbox={'edgecolor': 'none', 'facecolor': 'white', 'alpha': .5})
        axes['triggers'].set_ylabel('Frequency [Hz]')
        axes['triggers'].set_ylim(args.fmin, multiplier * fthresh)
        axes['triggers'].colorbar(cmap='YlGnBu', clim=(3, 100), norm='log',
                                  label='Signal-to-noise ratio')
        axes['segments'].set_ylim(-.55, .55)
        axes['segments'].text(
            0.01, 0.95,
            r'Time segments with $f\times%d > %.2f$ Hz' % (
                multiplier, fthresh),
            transform=axes['segments'].transAxes, va='top', ha='left',
            bbox={'edgecolor': 'none', 'facecolor': 'white', 'alpha': .5})
        for ax in axes.values():
            ax.set_epoch(int(args.gpsstart))
            ax.set_xlim(*span)
        png = '%s_SCATTERING_%s_HZ-%s.png' % (chanstr, tstr, gpsstr)
        try:
            plot.save(png)
        except OverflowError as e:
            warnings.warn(str(e))
            plot.axes[1].set_ylim(0, multiplier * fthresh)
            plot.refresh()
            plot.save(png)
        plot.close()
        logger.debug("%s written." % png)

        # make histogram
        histogram = Plot(figsize=[12, 6])
        ax = histogram.gca()
        hrange = (0, multiplier * fthresh)
        for m, color in list(zip(histdata, fringecolors))[::-1]:
            if histdata[m].size:
                ax.hist(
                    histdata[m], facecolor=color, alpha=.6, range=hrange,
                    bins=50, histtype='stepfilled', label=r'$f\times%d$' % m,
                    cumulative=-1, weights=ts.dx.value, bottom=1e-100,
                    log=True)
            else:
                ax.plot(histdata[m], color=color, label=r'$f\times%d$' % m)
                ax.set_yscale('log')
        ax.set_ylim(.01, float(livetime))
        ax.set_ylabel('Time with fringe above frequency [s]')
        ax.set_xlim(*hrange)
        ax.set_xlabel('Frequency [Hz]')
        ax.set_title(axes['position'].get_title())
        handles, labels = ax.get_legend_handles_labels()
        ax.legend(handles[::-1], labels[::-1], loc='upper right')
        hpng = '%s_SCATTERING_HISTOGRAM-%s.png' % (chanstr, gpsstr)
        histogram.save(hpng)
        histogram.close()
        logger.debug("%s written." % hpng)

        # write HTML
        if deadtime != 0 and effdt > 2:
            context = 'danger'
        elif ((deadtime != 0 and effdt < 2) or
              (histdata[multiplier].size and
               histdata[multiplier].max() >=
                  fthresh/2.)):
            context = 'warning'
        else:
            continue
        page.div(class_='card border-%s mb-1 shadow-sm' % context)
        page.div(class_='card-header text-white bg-%s' % context)
        page.a(channel, class_='collapsed card-link cis-link',
               href='#osem%s' % i, **{'data-toggle': 'collapse'})
        page.div.close()  # card-header
        page.div(id_='osem%s' % i, class_='collapse',
                 **{'data-parent': '#osems-group'})
        page.div(class_='card-body')
        page.div(class_='row')
        img = htmlio.FancyPlot(
            png, caption=SCATTER_CAPTION.format(CHANNEL=channel))
        page.div(class_='col-md-10 offset-md-1')
        page.add(htmlio.fancybox_img(img))
        page.div.close()  # col-md-10 offset-md-1
        himg = htmlio.FancyPlot(
            hpng, caption=HIST_CAPTION.format(CHANNEL=channel))
        page.div(class_='col-md-10 offset-md-1')
        page.add(htmlio.fancybox_img(himg))
        page.div.close()  # col-md-10 offset-md-1
        page.div.close()  # row
        segs = StringIO()
        if deadtime:
            page.p("%d segments were found predicting a scattering fringe "
                   "above %.2f Hz." % (
                       len(scatter_segments[channel].active),
                       fthresh))
            page.table(class_='table table-sm table-hover')
            page.tbody()
            page.tr()
            page.th('Deadtime')
            page.td('%.2f/%d seconds' % (deadtime, livetime))
            page.td('%.2f%%' % deadtimepc)
            page.tr.close()
            page.tr()
            page.th('Efficiency<br><small>(SNR&ge;8 and '
                    '%.2f Hz</sub>&ltf<sub>peak</sub>&lt;%.2f Hz)</small>'
                    % (args.fmin, multiplier * fthresh))
            page.td('%d/%d events' % (efficiency, len(highsnrtrigs)))
            page.td('%.2f%%' % efficiencypc)
            page.tr.close()
            page.tr()
            page.th('Efficiency/Deadtime')
            page.td()
            page.td('%.2f' % effdt)
            page.tr.close()
            page.tbody.close()
            page.table.close()
            scatter_segments[channel].active.write(segs, format='segwizard',
                                                   coltype=float)
            page.pre(segs.getvalue())
        else:
            page.p("No segments were found with scattering above %.2f Hz."
                   % fthresh)
        page.div.close()  # card-body
        page.div.close()  # collapse
        page.div.close()  # card

    if statea:  # close accordion
        page.div.close()  # osems-group

    # scattering based on transmon BLRMS
    if statea:
        page.h3('Transmons', class_='mt-3', id_='transmons')
        page.div(id_='transmons-group')
    logger.info('Searching for scatter based on band-limited RMS of transmons')

    for i, channel in enumerate(sorted(transmons)):
        logger.info("-- Processing %s --" % channel)
        optic = channel.split('-')[1][:6]
        flag = '%s:DCH-%s_SCATTERING_BLRMS:1' % (args.ifo, optic)
        scatter_segments[channel] = DataQualityFlag(
            flag,
            isgood=False,
            description="Evidence for scattering from whitened, band-limited "
                        "RMS trends of {0}".format(channel),
        )

        # loop over state segments and compute BLRMS
        for j, seg in enumerate(statea):
            logger.debug("Processing segment [%d .. %d)" % seg)
            wblrms = get_blrms(
                alldata[j][channel],
                flow=args.bandpass_flow,
                fhigh=args.bandpass_fhigh,
            )
            scatter = get_segments(
                wblrms,
                numpy.mean(wblrms) + args.sigma * numpy.std(wblrms),
                name=flag,
            )
            scatter_segments[channel] += scatter
            logger.debug(
                "    Found %d scattering segments" % (len(scatter.active)))
        logger.debug("Completed channel %s, found %d segments in total"
                     % (channel, len(scatter_segments[channel].active)))

        # calculate efficiency and deadtime of veto
        deadtime = abs(scatter_segments[channel].active)
        try:
            deadtimepc = deadtime / livetime * 100
        except ZeroDivisionError:
            deadtimepc = 0.
        logger.info("Deadtime: %.2f%% (%.2f/%ds)"
                    % (deadtimepc, deadtime, livetime))
        highsnrtrigs = trigs[trigs['snr'] <= 200]
        efficiency = in_segmentlist(highsnrtrigs[names[0]],
                                    scatter_segments[channel].active).sum()
        try:
            efficiencypc = efficiency / len(highsnrtrigs) * 100
        except ZeroDivisionError:
            efficiencypc = 0.
        logger.info("Efficiency (SNR>=8): %.2f%% (%d/%d)"
                    % (efficiencypc, efficiency, len(highsnrtrigs)))
        if deadtimepc == 0.:
            effdt = 0
        else:
            effdt = efficiencypc/deadtimepc
        logger.info("Efficiency/Deadtime: %.2f" % effdt)

        if abs(scatter_segments[channel].active):
            actives.extend(scatter_segments[channel].active)

        # write HTML
        if deadtime != 0 and effdt > 2:
            context = 'danger'
        elif deadtime != 0 and effdt < 2:
            context = 'warning'
        else:
            continue
        page.add(htmlio.write_flag_html(
            scatter_segments[channel], span, i, parent='transmons-group',
            title=channel, context=context, plotdir=''))

    if statea:  # close accordion
        page.div.close()  # transmons-group

    actives = actives.coalesce()  # merge contiguous segments
    if statea and not actives:
        page.add(htmlio.alert(
            'No evidence of scattering found in the channels analyzed',
            context=args.ifo.lower(), dismiss=False))

    # identify triggers during active segments
    logger.debug('Writing a summary CSV record')
    ind = [i for i, trigtime in enumerate(highsnrtrigs[names[0]])
           if trigtime in actives]
    gps = highsnrtrigs[names[0]][ind]
    freq = highsnrtrigs[names[1]][ind]
    snr = highsnrtrigs[names[2]][ind]
    segs = [y for x in gps for y in actives if x in y]
    table = EventTable(
        [gps, freq, snr, [seg[0] for seg in segs], [seg[1] for seg in segs]],
        names=('trigger_time', 'trigger_frequency', 'trigger_snr',
               'segment_start', 'segment_end'))
    logger.info('The following {} triggers fell within active scattering '
                'segments:\n\n'.format(len(table)))
    print(table)
    print('\n\n')
    table.write(summfile, overwrite=True)

    # -- launch omega scans -----------

    nscans = min(args.omega_scans, len(table))
    if nscans > 0:
        # launch scans
        scandir = 'scans'
        ind = random.sample(range(0, len(table)), nscans)
        omegatimes = [str(t) for t in table['trigger_time'][ind]]
        logger.debug('Collected {} event times to omega scan: {}'.format(
            nscans, ', '.join(omegatimes)))
        logger.info('Creating workflow for omega scans')
        flags = batch.get_command_line_flags(
            ifo=args.ifo, ignore_state_flags=True)
        condorcmds = batch.get_condor_arguments(timeout=4, gps=args.gpsstart)
        batch.generate_dag(omegatimes, flags=flags, submit=True,
                           outdir=scandir, condor_commands=condorcmds)
        logger.info('Launched {} omega scans to condor'.format(nscans))
        # render HTML
        page.h2('Omega scans', class_='mt-4', id_='omega-scans')
        msg = (
            'The following event times correspond to significant Omicron '
            'triggers that occur during the scattering segments found above. '
            'To compare these against fringe frequency projections, please '
            'use the "simple scattering" module:',
            markup.oneliner.pre(
                '$ python -m gwdetchar.scattering.simple --help',
            ),
        )
        page.add(htmlio.alert(msg, context=args.ifo.lower()))
        page.add(htmlio.scaffold_omega_scans(
            omegatimes, args.main_channel, scandir=scandir))
    elif args.omega_scans:
        logger.info('No events found during active scattering segments')

    # -- finalize ---------------------

    # write segments
    scatter_segments.write(segfile, path="segments", overwrite=True)
    logger.debug("%s written" % segfile)

    # write HTML
    htmlio.close_page(page, 'index.html')
    logger.info("-- index.html written, all done --")

    # return to original directory
    os.chdir(indir)