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Lowpass filtering of time series data

Source: R/pipeline-lpfilt.R
lpfilt.Rd

The intended use of this method is for smoothing, although by specifying wp and ws differently one can achieve highpass or bandpass filtering as well. However, only lowpass filtering should be done on pupillometry data.

Usage

lpfilt(
  eyeris,
  wp = 4,
  ws = 8,
  rp = 1,
  rs = 35,
  plot_freqz = FALSE,
  call_info = NULL
)

Arguments

eyeris

An object of class eyeris derived from load_asc()

wp

The end of passband frequency in Hz (desired lowpass cutoff). Defaults to 4

ws

The start of stopband frequency in Hz (required lowpass cutoff). Defaults to 8

rp

Required maximal ripple within passband in dB. Defaults to 1

rs

Required minimal attenuation within stopband in dB. Defaults to 35

plot_freqz

A flag to indicate whether to display the filter frequency response. Defaults to FALSE

call_info

A list of call information and parameters. If not provided, it will be generated from the function call. Defaults to NULL

Value

An eyeris object with a new column in timeseries: pupil_raw_{...}_lpfilt

Details

This function is automatically called by glassbox() by default. If needed, customize the parameters for lpfilt by providing a parameter list. Use glassbox(lpfilt = FALSE) to disable this step as needed.

Users should prefer using glassbox() rather than invoking this function directly unless they have a specific reason to customize the pipeline manually.

Note

This function is part of the glassbox() preprocessing pipeline and is not intended for direct use in most cases. Provide parameters via lpfilt = list(...).

Advanced users may call it directly if needed.

See also

glassbox() for the recommended way to run this step as part of the full eyeris glassbox preprocessing pipeline

Examples

demo_data <- eyelink_asc_demo_dataset()

demo_data |>
  # set lpfilt to FALSE (instead of a list of params) to skip step
  eyeris::glassbox(lpfilt = list(plot_freqz = TRUE)) |>
  plot(seed = 0)
#> ✔ [  OK  ] - Running eyeris::load_asc()
#> ℹ [ INFO ] - Processing block: block_1
#> ✔ [  OK  ] - Running eyeris::deblink() for block_1
#> ✔ [  OK  ] - Running eyeris::detransient() for block_1
#> ✔ [  OK  ] - Running eyeris::interpolate() for block_1
#> ✔ [  OK  ] - Running eyeris::lpfilt() for block_1

#> ! [ SKIP ] - Skipping eyeris::downsample() for block_1
#> ! [ SKIP ] - Skipping eyeris::bin() for block_1
#> ! [ SKIP ] - Skipping eyeris::detrend() for block_1
#> ✔ [  OK  ] - Running eyeris::zscore() for block_1
#> 
#> Block processing summary:
#>   block_1: OK (steps: 6, latest: pupil_raw_deblink_detransient_interpolate_lpfilt_z)
#> 
#> ✔ [  OK  ] - Running eyeris::summarize_confounds()
#> ! [ INFO ] - Plotting block 1 from possible blocks: 1
#> ℹ [ INFO ] - Plotting with sampling rate: 1000 Hz