specparam.SpectralModel

class specparam.SpectralModel(peak_width_limits=(0.5, 12.0), max_n_peaks=inf, min_peak_height=0.0, peak_threshold=2.0, aperiodic_mode='fixed', periodic_mode='gaussian', metrics=None, bands=None, debug=False, verbose=True, **model_kwargs)[source]

Model a power spectrum as a combination of aperiodic and periodic components.

WARNING: frequency and power values inputs must be in linear space. Passing in logged frequencies and/or power spectra is not detected, and will silently produce incorrect results.

Parameters:
peak_width_limitstuple of (float, float), optional, default: (0.5, 12.0)

Limits on possible peak width, in Hz, as (lower_bound, upper_bound).

max_n_peaksint, optional, default: inf

Maximum number of peaks to fit.

min_peak_heightfloat, optional, default: 0

Absolute threshold for detecting peaks. This threshold is defined in absolute units of the power spectrum (log power).

peak_thresholdfloat, optional, default: 2.0

Relative threshold for detecting peaks. Threshold is defined in relative units of the power spectrum (standard deviation).

aperiodic_mode{‘fixed’, ‘knee’}

Which approach to take for fitting the aperiodic component.

periodic_mode{‘gaussian’, ‘skewed_gaussian’, ‘cauchy’}

Which approach to take for fitting the periodic component.

metricsMetrics or list of Metric or list or str

Metrics definition(s) to use to evaluate the model.

bandsBands or dict or int or None, optional

Bands object with band definitions, or definition that can be turned into a Bands object.

debugbool, optional, default: False

Whether to run in debug mode. If in debug, any errors encountered during fitting will raise an error.

verbosebool, optional, default: True

Verbosity mode. If True, prints out warnings and general status updates.

**model_kwargs

Additional model fitting related keyword arguments.

Notes

  • Input power spectra must be provided in linear scale. Internally they are stored in log10 scale, as this is what the model operates upon.

  • Input power spectra should be smooth, as overly noisy power spectra may lead to bad fits. For example, raw FFT inputs are not appropriate. Where possible and appropriate, use longer time segments for power spectrum calculation to get smoother power spectra, as this will give better model fits.

Attributes:
algorithmAlgorithm

Algorithm object with model fitting settings and procedures.

modesModes

Modes object with fit mode definitions.

dataData

Data object with spectral data and metadata.

resultsResults

Results object with model fit results and metrics.

__init__(peak_width_limits=(0.5, 12.0), max_n_peaks=inf, min_peak_height=0.0, peak_threshold=2.0, aperiodic_mode='fixed', periodic_mode='gaussian', metrics=None, bands=None, debug=False, verbose=True, **model_kwargs)[source]

Initialize model object.

Methods

__init__([peak_width_limits, max_n_peaks, ...])

Initialize model object.

add_data(freqs, power_spectrum[, ...])

Add data (frequencies, and power spectrum values) to the current object.

add_modes(aperiodic_mode, periodic_mode)

Add modes definition to the object.

copy()

Return a copy of the current object.

fit([freqs, power_spectrum, freq_range, ...])

Fit a power spectrum as a combination of periodic and aperiodic components.

get_data([component, space])

Get a data component.

get_metrics(category[, measure])

Get requested metric(s) from the object.

get_params(component[, field])

Return model fit parameters for specified feature(s).

load(file_name[, file_path, regenerate])

Load in a data file to the current object.

plot([plot_peaks, plot_aperiodic, freqs, ...])

Plot the power spectrum and model fit results from a model object.

print_modes([description, concise])

Print out the current fit modes.

print_report_issue([concise])

Prints instructions on how to report bugs and/or problematic fits.

print_results([concise])

Print out model fitting results.

print_settings([description, concise])

Print out the current settings.

report([freqs, power_spectrum, freq_range, ...])

Run model fit, and display a report, which includes a plot, and printed results.

save(file_name[, file_path, append, ...])

Save out data, results and/or settings from a model object into a JSON file.

save_report(file_name[, file_path, add_settings])

Generate and save out a PDF report for a power spectrum model fit.

to_df([bands])

Convert and extract the model results as a pandas object.

add_data(freqs, power_spectrum, freq_range=None, clear_results=True)[source]

Add data (frequencies, and power spectrum values) to the current object.

Parameters:
freqs1d array

Frequency values for the power spectrum, in linear space.

power_spectrum1d array

Power spectrum values, which must be input in linear space.

freq_rangelist of [float, float], optional

Frequency range to restrict power spectrum to. If not provided, keeps the entire range.

clear_resultsbool, optional, default: True

Whether to clear prior results, if any are present in the object. This should only be set to False if data for the current results are being re-added.

Notes

If called on an object with existing data it will be cleared by this method call.

add_modes(aperiodic_mode, periodic_mode)

Add modes definition to the object.

Parameters:
aperiodic_modeMode or str

Mode for aperiodic component, or string specifying which mode to use.

periodic_modeMode or str

Mode for periodic component, or string specifying which mode to use.

copy()

Return a copy of the current object.

fit(freqs=None, power_spectrum=None, freq_range=None, prechecks=True)[source]

Fit a power spectrum as a combination of periodic and aperiodic components.

Parameters:
freqs1d array, optional

Frequency values for the power spectrum, in linear space.

power_spectrum1d array, optional

Power values, which must be input in linear space.

freq_rangelist of [float, float], optional

Frequency range to restrict power spectrum to. If not provided, keeps the entire range.

prechecksbool, optional, default: True

Whether to run model fitting pre-checks.

Raises:
NoDataError

If no data is available to fit.

FitError

If model fitting fails to fit. Only raised in debug mode.

Notes

Data is optional, if data has already been added to the object.

get_data(component='full', space='log')

Get a data component.

Parameters:
component{‘full’, ‘aperiodic’, ‘peak’}
Which data component to return.

‘full’ - full power spectrum ‘aperiodic’ - isolated aperiodic data component ‘peak’ - isolated peak data component

space{‘log’, ‘linear’}
Which space to return the data component in.

‘log’ - returns in log10 space. ‘linear’ - returns in linear space.

Returns:
output1d array

Specified data component, in specified spacing.

Notes

The ‘space’ parameter doesn’t just define the spacing of the data component values, but rather defines the space of the additive data definition such that power_spectrum = aperiodic_component + peak_component. With space set as ‘log’, this combination holds in log space. With space set as ‘linear’, this combination holds in linear space.

get_metrics(category, measure=None)[source]

Get requested metric(s) from the object.

Parameters:
Name of the specific measure(s) to return.
Returns:
metricsdict

Dictionary of requested metrics.

get_params(component, field=None)[source]

Return model fit parameters for specified feature(s).

Parameters:
fieldstr or int, optional

Column name / index to extract from selected data, if requested. If str, should align with a parameter label for the component fit mode.

version{‘fit’, ‘converted’}

Which version of the parameters to extract.

Returns:
outfloat or 1d array

Requested data.

Raises:
NoModelError

If there are no model fit parameters available to return.

Notes

If there are no fit peaks (no periodic parameters), this method will return NaN.

load(file_name, file_path=None, regenerate=True)[source]

Load in a data file to the current object.

Parameters:
file_namestr or FileObject

File to load data from.

file_pathPath or str, optional

Path to directory to load from. If None, loads from current directory.

regeneratebool, optional, default: True

Whether to regenerate the model fit from the loaded data, if data is available.

plot(plot_peaks=None, plot_aperiodic=True, freqs=None, power_spectrum=None, freq_range=None, plt_log=False, add_legend=True, ax=None, data_kwargs=None, model_kwargs=None, aperiodic_kwargs=None, peak_kwargs=None, **plot_kwargs)[source]

Plot the power spectrum and model fit results from a model object.

Parameters:
plot_peaksNone or {‘shade’, ‘dot’, ‘outline’, ‘line’}, optional

What kind of approach to take to plot peaks. If None, peaks are not specifically plotted. Can also be a combination of approaches, separated by ‘-’, for example: ‘shade-line’.

plot_aperiodicboolean, optional, default: True

Whether to plot the aperiodic component of the model fit.

freqs1d array, optional

Frequency values of the power spectrum to plot, in linear space. If provided, this overrides the values in the model object.

power_spectrum1d array, optional

Power values to plot, in linear space. If provided, this overrides the values in the model object.

freq_rangelist of [float, float], optional

Frequency range to plot, defined in linear space.

plt_logboolean, optional, default: False

Whether to plot the frequency values in log10 spacing.

add_legendboolean, optional, default: False

Whether to add a legend describing the plot components.

axmatplotlib.Axes, optional

Figure axes upon which to plot.

data_kwargs, model_kwargs, aperiodic_kwargs, peak_kwargsNone or dict, optional

Keyword arguments to pass into the plot call for each plot element.

**plot_kwargs

Additional plot related keyword arguments, with styling options managed by style_plot.

Notes

The y-axis (power) is plotted in log spacing by default.

print_modes(description=False, concise=False)

Print out the current fit modes.

Parameters:
descriptionbool, optional, default: False

Whether to print out a description with current fit modes.

concisebool, optional, default: False

Whether to print the report in a concise mode, or not.

static print_report_issue(concise=False)

Prints instructions on how to report bugs and/or problematic fits.

Parameters:
concisebool, optional, default: False

Whether to print the report in a concise mode, or not.

print_results(concise=False)[source]

Print out model fitting results.

Parameters:
concisebool, optional, default: False

Whether to print the report in a concise mode, or not.

print_settings(description=False, concise=False)

Print out the current settings.

Parameters:
descriptionbool, optional, default: False

Whether to print out a description with current settings.

concisebool, optional, default: False

Whether to print the report in a concise mode, or not.

report(freqs=None, power_spectrum=None, freq_range=None, plt_log=False, plot_full_range=False, **plot_kwargs)[source]

Run model fit, and display a report, which includes a plot, and printed results.

Parameters:
freqs1d array, optional

Frequency values for the power spectrum.

power_spectrum1d array, optional

Power values, which must be input in linear space.

freq_rangelist of [float, float], optional

Frequency range to fit the model to. If not provided, fits across the entire given range.

plt_logbool, optional, default: False

Whether or not to plot the frequency axis in log space.

plot_full_rangebool, default: False

If True, plots the full range of the given power spectrum. Only relevant / effective if freqs and power_spectrum passed in in this call.

**plot_kwargs

Keyword arguments to pass into the plot method. Plot options with a name conflict be passed by pre-pending ‘plot_’. e.g. freqs, power_spectrum and freq_range.

Notes

Data is optional, if data has already been added to the object.

save(file_name, file_path=None, append=False, save_results=False, save_settings=False, save_data=False)[source]

Save out data, results and/or settings from a model object into a JSON file.

Parameters:
file_namestr or FileObject

File to save data to.

file_pathPath or str, optional

Path to directory to save to. If None, saves to current directory.

appendbool, optional, default: False

Whether to append to an existing file, if available. This option is only valid (and only used) if ‘file_name’ is a str.

save_resultsbool, optional

Whether to save out model fit results.

save_settingsbool, optional

Whether to save out settings.

save_databool, optional

Whether to save out input data.

save_basebool, optional

Whether to save out base data. Can be set to False to remove redundant information when saving from multiple models.

Raises:
ValueError

If the save file is not understood.

save_report(file_name, file_path=None, add_settings=True, **plot_kwargs)[source]

Generate and save out a PDF report for a power spectrum model fit.

Parameters:
file_namestr

Name to give the saved out file.

file_pathPath or str, optional

Path to directory to save to. If None, saves to current directory.

add_settingsbool, optional, default: True

Whether to add a print out of the model settings to the end of the report.

plot_kwargskeyword arguments

Keyword arguments to pass into the plot method.

to_df(bands=None)[source]

Convert and extract the model results as a pandas object.

Parameters:
bandsBands or int, optional

How to organize peaks into bands. If Bands, extracts peaks based on band definitions. If int, extracts the first n peaks. If not provided, uses the bands definition available in the object.

Returns:
pd.Series

Model results organized into a pandas object.

Examples using specparam.SpectralModel

Dealing with Line Noise

Dealing with Line Noise

Exporting Model Results

Exporting Model Results

Failed Model Fits

Failed Model Fits

Fitting Power Spectrum Models Across 3D Arrays

Fitting Power Spectrum Models Across 3D Arrays

Manipulating Objects

Manipulating Objects

Aperiodic Parameters

Aperiodic Parameters

Exploring Data Components

Exploring Data Components

Frequency-by-Frequency Errors

Frequency-by-Frequency Errors

Periodic Parameters

Periodic Parameters

Plot Model Components

Plot Model Components

Plot Power Spectrum Models

Plot Power Spectrum Models

Transforming Power Spectra

Transforming Power Spectra

Developmental Data Demo

Developmental Data Demo

Topographical Analyses with MNE

Topographical Analyses with MNE

01: Model Description

01: Model Description

02: Fitting Power Spectrum Models

02: Fitting Power Spectrum Models

03: Fitting Algorithm

03: Fitting Algorithm

04: Periodic Component Fitting

04: Periodic Component Fitting

05: Aperiodic Component Fitting

05: Aperiodic Component Fitting

06: Metrics & Model Evaluation

06: Metrics & Model Evaluation

07: Exploring the model object

07: Exploring the model object

08: Fitting group of spectra

08: Fitting group of spectra

09: Fitting Models over Time

09: Fitting Models over Time

10: Tuning & Troubleshooting

10: Tuning & Troubleshooting

11: Further Analysis

11: Further Analysis

12: Reporting & Referencing

12: Reporting & Referencing

Band-by-Band

Band-by-Band