Internal function to downsample pupil data

This function downsamples pupil data by applying an anti-aliasing filter before decimation. Unlike binning, downsampling preserves the original temporal dynamics without averaging within bins.

This function is called by the exposed wrapper downsample().

Usage

downsample_pupil(x, prev_op, target_fs, plot_freqz, current_fs, rp, rs)

Arguments

x

A data frame containing pupil data with columns time_secs and the previous operation's pupil column

prev_op

The name of the previous operation's pupil column

target_fs

The target sampling frequency in Hz after downsampling

plot_freqz

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

current_fs

The current sampling frequency in Hz. Defaults to NULL

rp

Passband ripple in dB. Defaults to 1

rs

Stopband attenuation in dB. Defaults to 35

Value

A list containing the downsampled data and the decimated sample rate