Stata Coding Practices: Debugging

Debugging is the process of fixing runtime errors or other unexpected behaviors in Stata code. Unlike normal code execution, debugging involves intentionally preventing code from running completely so the user can investigate the current state of data or memory and determine what code would produce the desired outputs in a complete execution of the code.

Read First

Stata code is typically debugged using three tools: trace, pause, and display. Understanding how to use these tools interactively will allow you to pinpoint and correct errors in code.

• The trace command requests that Stata display additional levels of detail as it executes code. Nearly all Stata code and commands use other commands as part of their execution, and an appropriately set trace readout will allow you to pinpoint the line or command where an issue is occurring.
• The pause command freezes the execution of Stata code in the designated location and optionally displays information about Stata's memory state. While paused, Stata allows the user to interact with the data as it is at that point in code execution and to permit code execution to continue when finished.
• The display command is used to extract specific information about Stata's current state without pausing or tracing all code execution. Since Stata has rich information on hand at all times about macros and data in memory, it is possible to detect problems when unexpected or inappropriate values are displayed during code execution.