OPT_BINOMIAL(amer_euro_flag,call_put_flag,num_time_steps,spot,strike,time,rate,volatility,cost_of_carry)
amer_euro_flag: 'a' for an American style option or 'e' for a European style option
call_put_flag: 'c' for a call and 'p' for a put
num_time_steps: number of time steps used in the valuation
spot: spot price
strike: strike price
time: time to maturity in years
rate: annualized risk-free interest rate
volatility: annualized volatility of the asset
cost_of_carry: net cost of holding the underlying asset
A larger num_time_steps yields greater accuracy but OPT_BINOMIAL is slower to calculate.
OPT_BS, OPT_BS_DELTA, OPT_BS_RHO, OPT_BS_THETA, OPT_BS_GAMMA.