ARCHIVED: In Stata, how do I get aggregate statistics and save them into a data set?

This content has been archived, and is no longer maintained by Indiana University. Information here may no longer be accurate, and links may no longer be available or reliable.

Stata's collapse command computes aggregate statistics such as mean, sum, and standard deviation and saves them into a data set. When you execute the command, an existing data set is replaced with the new one containing aggregate data.

Suppose you want to get the sum of a variable x1 and the mean of a variable x2 for males and females separately. Consider the following example:

  . collapse (sum) x1 (mean) x2, by(male)

Note that male is set to 1 for male and 0 for female. The new data set has two observations with three variables: male, x1, and x2.

If you want to save into different variable names, specify the names, for example:

  . collapse (sum) new_x1=x1 (mean) new_x2=x2, by(male)

If you have questions about using statistical and mathematical software at Indiana University, contact the UITS Research Applications and Deep Learning team.

This is document aqdz in the Knowledge Base.
Last modified on 2018-01-18 14:34:04.