data/examples/paradigm_examples/plot_within_session_p300.py

"""
===========================
Within Session P300
===========================

This example shows how to perform a within session analysis on three different
P300 datasets.

We will compare two pipelines :

- Riemannian geometry
- XDAWN with Linear Discriminant Analysis

We will use the P300 paradigm, which uses the AUC as metric.

"""

# Authors: Pedro Rodrigues <pedro.rodrigues01@gmail.com>
#
# License: BSD (3-clause)

import warnings

import matplotlib.pyplot as plt
from mne.decoding import Vectorizer
from pyriemann.estimation import Xdawn, XdawnCovariances
from pyriemann.tangentspace import TangentSpace
from sklearn.discriminant_analysis import LinearDiscriminantAnalysis as LDA
from sklearn.pipeline import make_pipeline

import moabb
import moabb.analysis.plotting as moabb_plt
from moabb.analysis.chance_level import chance_by_chance
from moabb.datasets import BNCI2014_009
from moabb.evaluations import WithinSessionEvaluation
from moabb.paradigms import P300


##############################################################################
# getting rid of the warnings about the future
warnings.simplefilter(action="ignore", category=FutureWarning)
warnings.simplefilter(action="ignore", category=RuntimeWarning)

moabb.set_log_level("info")

##############################################################################
# Create Pipelines
# ----------------
#
# Pipelines must be a dict of sklearn pipeline transformer.


pipelines = {}

##############################################################################
# We have to do this because the classes are called 'Target' and 'NonTarget'
# but the evaluation function uses a LabelEncoder, transforming them
# to 0 and 1
labels_dict = {"Target": 1, "NonTarget": 0}

pipelines["RG+LDA"] = make_pipeline(
    XdawnCovariances(
        nfilter=2, classes=[labels_dict["Target"]], estimator="lwf", xdawn_estimator="scm"
    ),
    TangentSpace(),
    LDA(solver="lsqr", shrinkage="auto"),
)

pipelines["Xdw+LDA"] = make_pipeline(
    Xdawn(nfilter=2, estimator="scm"), Vectorizer(), LDA(solver="lsqr", shrinkage="auto")
)

##############################################################################
# Evaluation
# ----------
#
# We define the paradigm (P300) and use all three datasets available for it.
# The evaluation will return a DataFrame containing a single AUC score for
# each subject / session of the dataset, and for each pipeline.
#
# Results are saved into the database, so that if you add a new pipeline, it
# will not run again the evaluation unless a parameter has changed. Results can
# be overwritten if necessary.

paradigm = P300(resample=128)
dataset = BNCI2014_009()
dataset.subject_list = dataset.subject_list[:2]
datasets = [dataset]
overwrite = True  # set to True if we want to overwrite cached results
evaluation = WithinSessionEvaluation(
    paradigm=paradigm, datasets=datasets, suffix="examples", overwrite=overwrite
)
results = evaluation.process(pipelines)

##############################################################################
# Plot Results
# ----------------
#
# Here we plot the results using the MOABB score plot with chance level
# annotations. The P300 paradigm has 2 classes (Target / NonTarget) with
# a theoretical chance level of 50%.

chance_levels = chance_by_chance(results, alpha=[0.05, 0.01])

fig, _ = moabb_plt.score_plot(results, chance_level=chance_levels)
plt.show()