AVGPRICE - Average Price
函数名：AVGPRICE
名称：平均价格函数
real = AVGPRICE(open, high, low, close)
Learn more about the Average Price at tadoc.org.
MEDPRICE - Median Price
函数名：MEDPRICE
名称：中位数价格
real = MEDPRICE(high, low)
Learn more about the Median Price at tadoc.org.
TYPPRICE - Typical Price
函数名：TYPPRICE
名称：代表性价格
real = TYPPRICE(high, low, close)
Learn more about the Typical Price at tadoc.org.
WCLPRICE - Weighted Close Price
函数名：WCLPRICE
名称：加权收盘价
real = WCLPRICE(high, low, close)