plot_psd: Plot Power Spectral Density

In neuroconductor/eegUtils: Utilities for Electroencephalographic (EEG) Analysis

Plot Power Spectral Density

Description

Calculate and plot the PSD for eeg_* objects. Output units are dB. The PSD is calculated using Welch's method.

Usage

plot_psd(data, freq_range = NULL, ...)

## S3 method for class 'eeg_epochs'
plot_psd(
  data,
  freq_range = NULL,
  n_fft = 256,
  seg_length = NULL,
  noverlap = NULL,
  demean = TRUE,
  keep_trials = TRUE,
  ...
)

## S3 method for class 'eeg_data'
plot_psd(
  data,
  freq_range = NULL,
  n_fft = 2048,
  noverlap = NULL,
  seg_length = NULL,
  ...
)

## S3 method for class 'eeg_ICA'
plot_psd(
  data,
  freq_range = NULL,
  components = NULL,
  seg_length = NULL,
  noverlap = NULL,
  n_fft = 256,
  ...
)

## S3 method for class 'data.frame'
plot_psd(data, freq_range = NULL, ...)

## S3 method for class 'eeg_evoked'
plot_psd(
  data,
  freq_range = NULL,
  n_fft = 256,
  seg_length = NULL,
  noverlap = NULL,
  keep_trials = TRUE,
  ...
)

## S3 method for class 'eeg_group'
plot_psd(
  data,
  freq_range = NULL,
  n_fft = 256,
  seg_length = NULL,
  noverlap = NULL,
  demean = TRUE,
  ...
)

Arguments

data	Object of class eeg_epochs, eeg_data, or eeg_ICA.
freq_range	Vector of lower and upper frequencies to plot. (e.g. c(1, 40))
...	Additional parameters.
n_fft	Number of points to use for the underlying FFTs. Defaults to 256 for eeg_epochs or minimum of 2048 or the signal length for eeg_data.
seg_length	Length of individual segments. Defaults to n_fft. Must be <= n_fft.
noverlap	Amount of overlap between segments, in sampling points. Defaults to 50%.
demean	Remove epoch means before FFT.
keep_trials	Whether to keep trial information in the output or average over all trials
components	Which components to compute the PSD for. Defaults to all.

Details

Welch's method splits the data into multiple segments and then averages over those segments. For epoched data, Welch's FFT is calculated separately for each trial.

Specific parameters such as the number of FFT points and the amount of overlap between segments can be passed to Welch's FFT.

Value

A ggplot object.

Methods (by class)

• eeg_epochs: Plot PSD for eeg_epochs.

• eeg_data: Plot PSD for eeg_data.

• eeg_ICA: Plot PSD for eeg_ICA objects

• data.frame: Plot PSD for data.frames.

• eeg_evoked: Plot PSD for eeg_evoked objects

• eeg_group: Plot PSD for eeg_group objects is not currently supported

Author(s)

Matt Craddock, [e-mail]

Examples

 plot_psd(demo_epochs)
 plot_psd(demo_epochs, seg_length = 256)

neuroconductor/eegUtils documentation built on Feb. 3, 2023, 5:33 p.m.