Data for people in a family, firms in a sector, or members of any kind of group are often analyzed using data for the other members in each group. Examples are the number of older children for each child in a family or the mean investment of other firms in the same year. Many such problems yield...

Three user-written commands are reviewed as illustrations of different approaches to tabulation problems, each one step beyond what is possible to do directly through official Stata. tabcount is a wrapper for tabdisp written to produce tables that show how often specified values occur or...

The great divide among data types in Stata is between numeric and string variables. Most of the time, which kind you want to use for particular variables is clear and unproblematic, but surprisingly often,users face difficulties in making the right decision or need to convert variables from one...

Functions in Stata take two main forms, built-in functions that are part of the executable and egen functions written in Stata's own language. These are surveyed, giving a variety of tips and tricks, and noting the large number of user-written egen functions available for download from the...

Program concord implements L. I. Lin Õs concordance correlation coefficient (Lin,1989), as well as the limits-of-agreement procedure (Bland and Altman, 1986). Recently, Lin (2000) issued an erratum reporting a number of typographical errors in his seminal 1989 paper. Further, changes in Stata...

Three commands in official Stata, foreach, forvalues, and for, provide structures for cycling through lists of values (variable names, numbers, arbitrary text) and repeating commands using members of those lists in turn. All these commands may be used interactively, and none is restricted to use...

Tables in some form or another are part and parcel of data management and analysis. The main general-purpose tabulation commands, tabulate, table, and tabstat, are reviewed and compared. When these do not provide a tabulation solution, one key strategy is to prepare the material for tabulation...