一个股票在线行情源代码，brew hexin,整个代码比较全。-A stock online market source code, brew hexin, compare the whole entire code.

本段代码使用quantOS系统实现了Markowitz资产组合优化，并画出有效前沿。并比较两组股票组合有效前沿的差异(This code uses the QuantOS system to implement Markowitz portfolio optimization and draws a valid frontier. And compare the difference between the effective frontiers of the two stock combina