FunctionBlackScholesLibrary   "FunctionBlackScholes" 
Some methods for the Black Scholes Options Model, which demonstrates several approaches to the valuation of a European call.
// reference:
//      people.math.sc.edu
//      people.math.sc.edu
 asset_path(s0, mu, sigma, t1, n)  Simulates the behavior of an asset price over time.
  Parameters:
     s0 : float, asset price at time 0.
     mu : float, growth rate.
     sigma : float, volatility.
     t1 : float, time to expiry date.
     n : int, time steps to expiry date.
  Returns: option values at each equal timed step (0 -> t1)
 binomial(s0, e, r, sigma, t1, m)  Uses the binomial method for a European call.
  Parameters:
     s0 : float, asset price at time 0.
     e : float, exercise price.
     r : float, interest rate.
     sigma : float, volatility.
     t1 : float, time to expiry date.
     m : int, time steps to expiry date.
  Returns: option value at time 0.
 bsf(s0, t0, e, r, sigma, t1)  Evaluates the Black-Scholes formula for a European call.
  Parameters:
     s0 : float, asset price at time 0.
     t0 : float, time at which the price is known.
     e : float, exercise price.
     r : float, interest rate.
     sigma : float, volatility.
     t1 : float, time to expiry date.
  Returns: option value at time 0.
 forward(e, r, sigma, t1, nx, nt, smax)  Forward difference method to value a European call option.
  Parameters:
     e : float, exercise price.
     r : float, interest rate.
     sigma : float, volatility.
     t1 : float, time to expiry date.
     nx : int, number of space steps in interval (0, L).
     nt : int, number of time steps.
     smax : float, maximum value of S to consider.
  Returns: option values for the european call, float array of size ((nx-1) * (nt+1)).
 mc(s0, e, r, sigma, t1, m)  Uses Monte Carlo valuation on a European call.
  Parameters:
     s0 : float, asset price at time 0.
     e : float, exercise price.
     r : float, interest rate.
     sigma : float, volatility.
     t1 : float, time to expiry date.
     m : int, time steps to expiry date.
  Returns: confidence interval for the estimated range of valuation.
