The function directly computes the volatility of assets σA from the time series A1,…,An as the annualized standard deviation of the log returns. This value is a single volatility value that captures the volatility of the assets during the time period spanned by the time series.After computing the values of A and σA, the function computes the distance to default (DD) is computed as the number of standard deviations between the expected asset value at maturity T and the liability threshold: