Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
David Peng <david.peng99@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
st: generate a column of a summary statistic conditioning on the comparison of the values in two other columns |

Date |
Wed, 5 Dec 2012 10:29:49 -0600 |

I have a dataset with four variables, A, B, C, and D. A is a variable representing the customer number. B is the main variable of interest (in this case the dollar amount of a customer order). C is the date a customer order was placed and D is the date the same customer order was delivered. I would like to generate a column of summary statistic (let's say I want the mean) in the table. Basically, for each customer order, I would like to generate a mean value of the dollar amount for all of the orders placed by a customer prior to the date the order is placed. For each observation (i.e., a cusomer order) in the data table, I would like to get: bysort A: egen mean_dollar_amount=mean(B) if B is associated with a delivery date D that is earlier than the order date C of the customer order in question. As an example, if I have an obervation representing an order placed by the customer x with the order date of 12/30/2011, I would like to generate the mean of the dollar amount for all of the orders that were delivered earlier than the order date of 12/30/2011 for the order mentioned above. I need a mean value like this for each observation (i.e., customer order) in the data. Thanks in advance for your help. * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: generate a column of a summary statistic conditioning on the comparison of the values in two other columns***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: generate a column of a summary statistic conditioning on the comparison of the values in two other columns***From:*Ronnie Babigumira <rb.glists@gmail.com>

- Prev by Date:
**Re: st: stcurve: why two different graphs?** - Next by Date:
**Re: st: generate a column of a summary statistic conditioning on the comparison of the values in two other columns** - Previous by thread:
**st: mvrs: out-of-sample prediction/definition of the splines** - Next by thread:
- Index(es):