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Plot ERP Filter GUI ​

This demo shows how to use the interactive filter GUI to explore the effect of different filter settings on ERP waveforms.

Why an Interactive Filter Tool? ​

  • Teaching — show students how filters affect ERP signals in real time

  • Parameter selection — experiment with cutoff frequency and filter order before committing

  • Method comparison — toggle between IIR (Butterworth) and FIR filters, filtfilt vs filt

Key Features ​

FeatureDescription
Lowpass / Highpass togglesEnable each filter independently
Cutoff slidersAdjust frequency in real time
Order slidersChange filter steepness
Method menuSwitch between Butterworth and FIR
Mirror toggleEnable mirror padding to reduce edge artifacts
Multi-conditionCompare filter effects across conditions side-by-side

What You'll Learn ​

  1. Launching the GUI for a single ERP

  2. Focusing on a specific channel

  3. Comparing filter effects across multiple conditions

Code Examples ​

Show Code
julia
# Demo: ERP Filter GUI
# Shows how to launch the interactive filter exploration tool
# to compare the effect of different filter settings on ERP waveforms.

using EegFun
# Note: EegFun.example_path() resolves bundled example data paths.
# When using your own data, simply pass the file path directly, e.g.:
# dat = EegFun.read_raw_data("/path/to/your/data.bdf")

#######################################################################
# LOAD DATA AND CREATE ERPS
#######################################################################

dat = EegFun.read_raw_data(EegFun.example_path("data/bdf/example1.bdf"))
layout = EegFun.read_layout(EegFun.example_path("layouts/biosemi/biosemi72.csv"))
EegFun.polar_to_cartesian_xy!(layout)
dat = EegFun.create_eegfun_data(dat, layout)

# Some minimal preprocessing (average reference and highpass filter)
EegFun.rereference!(dat, :avg)
EegFun.highpass_filter!(dat, 0.5)

# EPOCHS
epoch_cfg = EegFun.EpochCondition(name = "ExampleEpoch1", trigger_sequences = [[1]])
epochs = EegFun.extract_epochs(dat, epoch_cfg, (-0.5, 1.0))

# Create ERP
erp = EegFun.average_epochs(epochs)

# interactive GUI with sliders for cutoff, order, method
EegFun.plot_erp_filter_gui(erp)

See Also ​