Using a Variety of Advanced Functions
The LAG Function
A Brief Overview
Suppose you have the Certadv.Stock6Mon data set that contains opening and closing stock prices for the past six months for two different companies. You are trying to determine which company has the bigger difference in the daily opening price between consecutive days.
To start, consider what you want the LAG function to return, as shown below.
Figure 14.1 Desired LAG Function Results for ABC Company, by Day
The LAG function enables you to compare the daily opening prices between consecutive days by retrieving the previous values of a column from the last time that ...