// Utility functions
function calculateStats(data) {
    if (!data || data.length === 0) return { mean: 0, std: 0 };
    
    const mean = data.reduce((a, b) => a + b, 0) / data.length;
    const variance = data.reduce((a, b) => a + Math.pow(b - mean, 2), 0) / data.length;
    const std = Math.sqrt(variance);
    
    return { mean, std };
}

// Export other utility functions...