analysis.lc_colors

The lc_colors module fits tabulates the chi-squared values for colors modeled by an SNCosmo model. It also tabulates modeled and observed delta color over 15 days.

Function Documentation

analysis.lc_colors.calc_color_chisq(data_table, model, band1, band2, interval=1, prange=None)

Calculate the chi-squared for observed and modeled color

Assumes time values in the data and model are relative to the same zero point.

Parameters:

• data_table (Table) – Data table from sndata (format_sncosmo=True)
• model (Model) – An sncosmo model
• band1 (str) –
• band2 (str) –
• interval (int) – Spacing between phases when summing chisq
• prange (tuple) – Optional start and end phase for color evolution

Returns:

• The chi-square value
• The degrees of freedom

analysis.lc_colors.create_empty_output_table(color_bands, suffixes)

Create an empty astropy table for storing color dependant values

Returns an empty table with columns for each color defined by color_bands. Additional columns can be added with the same names but with an added suffix by specifying the suffixes argument.

Parameters:

• color_bands (list[Tuple]) – List of tuples with two band names
• suffixes (list[str]) – Include additional columns with suffixes

Returns:

An empty, masked astropy table

analysis.lc_colors.get_observed_color_times(data, band1, band2)

Return the time range for which observations overlap in two band passes

Parameters:

• data (Table) – Astropy table with columns ‘band’ and ‘time’
• band1 (str) – The name of a bandpass in data[‘band’]
• band2 (str) – The name of a bandpass in data[‘band’]

Returns:

The start time The end time

analysis.lc_colors.tabulate_chisq(data_release, models, colors, interval=1, prange=None, out_path=None)

Tabulate color chi-squared for multiple models

Integrate the chi-squared of the color evolution over the phase range prange. The phase range should be specified relative to B-band max. If prange is not specified, use the largest integration range allowed by the data on a color by color basis.

Parameters:

• data_release (module) – An sndata data release
• models (list) – A list of sncosmo models
• colors (list) – List of tuples with band names
• interval (int) – Spacing between phases when summing chisq
• prange (tuple) – Optional start and end phases
• out_path (str) – Optionally write to path with each iteration

analysis.lc_colors.tabulate_delta_15(data_release, models, band_combos, out_path=None, t0_band='csp_dr3_B')

Tabulate observed and modeled delta color over 15 days

Parameters:

• data_release (module) – An sndata data release
• models (list) – A list of sncosmo models
• band_combos (list) – List of tuples with band names
• out_path (str) – Optionally write to path with each iteration
• t0_band (str) – Band to use when setting model t0 to peak

Returns:

An astropy table