Plotting

The plotting helpers visualize sampled distributions, spectra, realization ensembles, and HEALPix skymaps.

plot_binned_spectrum

plot_binned_spectrum(spec, freqs=None, hc2_values=None)

Plot a PTA-binned characteristic-strain spectrum.

Parameters:

• spec ((array - like, shape(n_bins, 2))) –

  Two-column spectrum array returned by fastropop.binning. Column 0 contains \(\log_{10} f\), while column 1 contains the binned \(f h_c^2\)-style quantity before the final square root and logarithm are applied for display.

• freqs (array - like, default: None ) –

  Observer-frame reference frequencies in Hz for an overplotted smooth comparison curve.

• hc2_values (array - like, default: None ) –

  Reference characteristic-strain values or equivalent comparison curve to plot against the binned realization.

plot_sample_distributions

plot_sample_distributions(distM, distz, distlog10f, Mgrid, pdfM, zgrid, pdfz, fgrid_log10, pdflogf)

Plot sampled distributions against the target PDFs used for inverse-CDF sampling.

Parameters:

• distM (array - like) –

  Sampled chirp masses returned by fastropop.SemiAnalyticPopulation.sample_dist.

• distz (array - like) –

  Sampled redshifts returned by fastropop.SemiAnalyticPopulation.sample_dist.

• distlog10f (array - like) –

  Sampled \(\log_{10} f\) values returned by fastropop.SemiAnalyticPopulation.sample_dist.

• Mgrid (array - like) –

  Mass grid used to define the target mass PDF.

• pdfM (array - like) –

  Target mass PDF evaluated on Mgrid.

• zgrid (array - like) –

  Redshift grid used to define the target redshift PDF.

• pdfz (array - like) –

  Target redshift PDF evaluated on zgrid.

• fgrid_log10 (array - like) –

  Frequency grid in \(\log_{10} f\).

• pdflogf (array - like) –

  Target PDF evaluated on fgrid_log10.

plot_realizations

plot_realizations(log10f, yvals, median, q_low, q_high, freqs=None, hc2_values=None)

Plot many Monte Carlo realizations and their central interval.

Parameters:

• log10f (array - like) –

  Frequency-bin centers in \(\log_{10} f\).

• yvals ((array - like, shape(n_realizations, n_bins))) –

  Realization values, usually \(\log_{10}(h_c)\) after binning.

• median (array - like) –

  Pointwise median of the realization ensemble.

• q_low (array - like) –

  Lower envelope of the central interval.

• q_high (array - like) –

  Upper envelope of the central interval.

• freqs (array - like, default: None ) –

  Optional smooth comparison frequency grid in Hz.

• hc2_values (array - like, default: None ) –

  Optional smooth comparison strain curve.

plot_skymap

plot_skymap(skymaps, freq_index=0, polarization='total', log_scale=False, title=None)

Plot a single HEALPix skymap slice for one PTA frequency bin.

Parameters:

• skymaps (array - like) –

  Either a stacked array of shape (2, npix, n_frequencies) containing plus and cross polarizations, or a single array of shape (npix, n_frequencies).

• freq_index (int, default: 0 ) –

  Frequency-bin index to display.

• polarization (('total', 'plus', 'cross'), default: "total" ) –

  Which polarization content to visualize. For stacked maps, "total" shows \(\sqrt{|h_+|^2 + |h_\times|^2}\).

• log_scale (bool, default: False ) –

  If True, display \(\log_{10}\) of the amplitude.

• title (str, default: None ) –

  Plot title. If omitted, a descriptive default is created.