md_future query future market data from sina finance, https://finance.sina.com.cn/futuremarket/.
md_future(symbol, type = "history", date_range = "max", from = NULL, to = Sys.Date(), freq = "daily", print_step = 1L, ...)
future symbols It is available via function
md_future_symbol or its website.
the data type, including history, real and info. Default is history.
date range. Available value includes '1m'-'11m', 'ytd', 'max' and '1y'-'ny'. Default is max.
the start date. Default is NULL. If it is NULL, then calculate using date_range and end date.
the end date. Default is the current date.
data frequency, default is daily.
a non-negative integer, which will print symbol name by each print_step iteration. Default is 1L.