Simulates a matrix consisting of synthetic data for daily buys and sells
simulateBS(param, ndays)numeric: (named) vector of model parameters
(valid names: 'alpha', 'delta', 'epsilon_b', 'epsilon_s', 'mu'),
length must equal 5
integer: Number of trading days for which aggregated buys and sells are simulated, defaults to 60
numeric: Matrix with ndays rows and two columns which are named 'Buys' and 'Sells'.
If names are not set for param or one or more of the vector names do not match the valid choices, they are internally set to
'alpha', 'delta', 'epsilon_b', 'epsilon_s', 'mu' (in this order).