example_scripts/02_heatmap_density.py

"""
Traffic Density Heatmap — Automatum Data Full Highway Dataset
Generates a 2D heatmap of all vehicle positions over time.

Usage:
    python 02_heatmap_density.py <path_to_recording_folder>

Example:
    python 02_heatmap_density.py ../hw-a9-denkendorf-001-d8087340-8287-46b6-9612-869b09e68448

Output:
    traffic_heatmap.png in the current directory
"""
import sys
import os
import numpy as np
import matplotlib.pyplot as plt
from openautomatumdronedata.dataset import droneDataset


def generate_density_heatmap(dataset_path, output_filename="traffic_heatmap.png"):
    print(f"Loading dataset from: {dataset_path}")
    dataset = droneDataset(dataset_path)
    dynWorld = dataset.dynWorld

    print("Extracting position data...")
    all_x, all_y = [], []

    for dynObj in dynWorld.dynamicObjects.values():
        x_valid = [x for x in dynObj.x_vec if not np.isnan(x)]
        y_valid = [y for y in dynObj.y_vec if not np.isnan(y)]
        all_x.extend(x_valid)
        all_y.extend(y_valid)

    if not all_x:
        print("No position data found!")
        return

    print(f"Extracted {len(all_x)} data points. Creating heatmap...")

    plt.figure(figsize=(16, 6))
    plt.style.use("dark_background")
    plt.hist2d(all_x, all_y, bins=(300, 100), cmap="inferno", cmin=1)
    plt.colorbar(label="Traffic density (data points)")
    plt.title("Highway Traffic Density Heatmap (Top-View)")
    plt.xlabel("X-Position [m]")
    plt.ylabel("Y-Position [m]")
    plt.gca().set_aspect("equal", adjustable="box")
    plt.tight_layout()
    plt.savefig(output_filename, dpi=300)
    print(f"Heatmap saved: {os.path.abspath(output_filename)}")


if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: python 02_heatmap_density.py <path_to_recording_folder>")
    else:
        generate_density_heatmap(sys.argv[1])