Source code for mercurial.tests.enhancements.test_jansen_rit

"""Test Jansen‑Rit neural mass model with noise and time‑varying input."""

import matplotlib.pyplot as plt
import numpy as np

from mercurial.simulation.engine import SimulationEngine



[docs]
def pulsed_input(t):
    if t < 0.2:
        return 100.0  # initial pulse
    else:
        return 50.0  # lower sustained input



engine = SimulationEngine(dim=10)
results = engine.run_jansen_rit(
    (0.0, 2.0), dt=0.0005, n_columns=1, coupling_strength=0.0, external_input=pulsed_input
)

# Plot
plt.figure(figsize=(12, 4))
plt.plot(results["t"], results["EEG"])
plt.xlabel("Time (s)")
plt.ylabel("EEG (mV)")
plt.title("Jansen‑Rit Column Output (with noise and pulsed input)")
plt.grid(True, alpha=0.3)
plt.show()

print(f"Final EEG: {results['final_EEG']:.4f} mV")

# Compute standard deviation only if enough points exist
eeg_data = results["EEG"]
if len(eeg_data) > 1:
    # Use the second half of the data to avoid initial transient
    half = len(eeg_data) // 2
    eeg_std = np.std(eeg_data[half:])
    print(f"EEG std (second half): {eeg_std:.4f}")
else:
    print("Not enough data points to compute standard deviation.")