backtest_initialize: Unexported Subfunction(s) of backtest
In jmuhlenkamp/tidalbacktest: Package for Backtesting

Takes a set of daily prices and daily weights and returns a list of initialized data ready to be traded.

1 2	backtest_initialize(df_prices, df_weights, use_cash_long, use_cash_short, name)

`df_prices`	a data.frame containing the columns: symbol, date, price
`df_weights`	a data.frame containing the columns: symbol, date, w
`use_cash_long`	if TRUE use _CASH_LONG_ price within df_prices, else use 1 for all dates
`use_cash_short`	if TRUE use _CASH_SHORT_ price within df_prices, else use 1 for all dates
`name`	a string name for the backtest results