Re: st: How to refer to different time periods when writing code

[Nick Cox <njcoxstata@gmail.com>]

. help subscripting (to learn about [_n - 1] etc.)
. help varlist (for time-series operators: better for panel data)

Nick

On Fri, Jan 6, 2012 at 11:18 PM, Jessica Kopsic <jkops@andrew.cmu.edu> wrote:

> I'm new to using Stata with panel data and time series. I'm trying to
> create a variable that refers to different time periods.
> For each day, I have two questions:
> Did you eat an apple today? (yes/no)
> Did you eat an orange yesterday? (yes/no)
> Foe each individual for each day I would like to create a variable called
> Fruit, that would tell how many pieces of fruit a person had each day. But
> I'm stuck because orange is referring to the previous day. I do have a
> variable identifying the time periods - "Day" with values  1, 2, 3, etc.
> So if on Day 3 someone answered yes to the apple question and on Day 4
> someone answered yes to the orange question, the value for Fruit for Day 3
> would be 2.
> I'm not certain how to tell Stata "the previous day" or "the next day"
> when computing the variable.

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