test.py

import h5py
import matplotlib.pyplot as plt
import numpy as np

# Path to the H5 dataset
h5_file_path = "./data/your_dataset.h5"

# Open the HDF5 file
with h5py.File(h5_file_path, "r") as f:
    # Load datasets
    ppg_data = f["PPG"][:]  # PPG signals
    bp_labels = f["label"][:]  # BP labels (systolic, diastolic)
    subject_idx = f["subject_idx"][:]  # Subject IDs
    
# Extract first sample (first 875 points)
ppg_signal = ppg_data[0]  # First PPG window (7s)
systolic_bp, diastolic_bp = bp_labels[0]  # First BP label

# Time axis (assuming 125 Hz sampling rate → 7s window)
time_axis = np.linspace(0, 7, num=875)

# Plot PPG signal
plt.figure(figsize=(10, 4))
plt.plot(time_axis, ppg_signal, label="PPG Signal", color="blue")
plt.axhline(y=systolic_bp, color='red', linestyle='--', label=f"Systolic BP: {systolic_bp}")
plt.axhline(y=diastolic_bp, color='green', linestyle='--', label=f"Diastolic BP: {diastolic_bp}")

# Labels and legend
plt.xlabel("Time (seconds)")
plt.ylabel("PPG Amplitude")
plt.title("PPG Signal with Blood Pressure Labels")
plt.legend()
plt.grid(True)

# Show plot
plt.show()