3. Plotting an
EventTable as 2-d tiles¶
I would like to study the event triggers generated by the ExcessPower gravitational-wave burst detection algorithm, over a small stretch of data.
The data from which these events were generated contain a simulated gravitational-wave signal, or hardware injection, used to validate the performance of the LIGO detectors and downstream data analysis procedures.
First, we import the
EventTable object and read in a set of events from
a LIGO_LW-format XML file containing a
from gwpy.table import EventTable events = EventTable.read( 'H1-LDAS_STRAIN-968654552-10.xml.gz', tablename='sngl_burst', columns=['peak', 'central_freq', 'bandwidth', 'duration', 'snr'])
Here we manually specify the
columns to read in order to optimise
read() operation to parse only the data we actually need.
We can make a plot of these events as 2-dimensional tiles by specifying the x- and y-axis columns, and the widths in those directions:
plot = events.tile('peak', 'central_freq', 'duration', 'bandwidth', color='snr') ax = plot.gca() ax.set_yscale('log') ax.set_ylabel('Frequency [Hz]') ax.set_epoch(968654552) ax.set_xlim(968654552, 968654552+10) ax.set_title('LIGO-Hanford event tiles for HW100916') ax.colorbar(clim=[1, 8], cmap='YlGnBu', label='Signal-to-noise ratio (SNR)') plot.show()