def check_event_coverage(patterns, event_list):
    """Calculate the ratio of patterns that were extracted."""
    proportions = []
    for pattern_list in patterns:
        proportion = 0
        for pattern in pattern_list:
            for node in pattern.nodes():
                if node in event_list:
                    proportion += 1.0 / len(pattern_list)
                    break
        proportions.append(proportion)
    return proportions
Calculate the ratio of patterns that were extracted.