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 sngl_burst table

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"])

Note

Here we manually specify the columns to read in order to optimise the 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()

(png)

../../../_images/tiles-2.png