Praat scripting basics

1. Praat scripting basics Pauline Welby Coláiste na Tríonóide, Baile Átha Cliath (Irlanda) welbyp@tcd.ie

2. Praat scripting • Praat is a phonetic analysis software program • Available for many different platforms (Windows, Macintosh, Unix, Linux) • Can be downloaded (for free) from www.praat.org. • Includes a scripting language

3. Praat scripts • Do anything you can do in Praat by hand • Open, save, rename files, convert formats, etc. • Measure formants, F0, etc. • Resynthesize duration, F0, etc. • Draw figures • Label • Present stimuli and collect responses

4. Why script in Praat? • saves time • prevents errors (typos, data transfer errors) • makes errors easier/faster to correct • allows you to play around with different parameters

5. Detailed Praat scripting tutorial Available on the web (Praat web page): http://www.fon.hum.uva.nl/praat/manual/Scripting.html or From within Praat In objects window: Help | Praat intro Search: scripting

6. Keep in mind… • It’s easier to adapt an existing script (your own or someone else’s) than to write one from scratch. • Many scripts freely available on the WebCheck sites: • http://www.icp.inpg.fr/~welby/PAGES/praat.html (Pauline Welby, in French and English) • http://www.cavi.univ-paris3.fr/ilpga/ED/student/stcg/#E (Cedric Gendrot, in French) • http://www.helsinki.fi/~lennes/praat-scripts(Mietta Lennes, in English) • http://www.icp.inpg.fr/%7Eloeven/ScriptsPraat.html(Hélène Loevenbruck, in French) • http://www.cphling.dk/pers/johtnd/praat/my_praat.htm(John Tøndering, in English) • http://www.ling.ohio-state.edu/~kyoon/scripts/praat(Kyuchul Yoon, in English) Also, try a Google search.

7. Opening a Praat script • To open an existing script in Praat: Praat | Open script... • Note: Different from opening sound files, TextGrid files etc. (Read | Read from file…)

8. Let’s try it… • Open (read in) all sound files in a directory • Can do by hand (slowly and painfully) • Or use a script: readin-files-simple.praat - Praat | Open script... - Navigate to correct directory and find readin-files-simple.praat

9. Open the script: Starter1.praat

10. Elements in a script Comments • Allow you to give descriptions of what each part of a script does • A very good idea! Helps you (and other users) understand how the script works • Also useful for testing and diagnostic purposes • Praat comment character: # • Praat ignores anything to the right of # • This line reads in a sound file: Read from file... finger.wav • This line does nothing! #Read from file... finger.wav

11. Elements in a script • Objects (are manipulated) • everything in object window (at left) • files • numbers • strings (letters, etc.) …

12. Open the script: Starter2.praat

13. Elements in a script • Variables (a type of object) • Store values • Examples: • ifile • numberOfFiles • fileName$ • Types: number, string (text), boolean (yes/no or 1/0) • Naming conventions: • begin with lowercase letters • no spaces • string variables must end in ‘$’

14. Open the script: Starter3.praat

15. Elements in a script • Functions (exist in Praat window menus) • Read from file… • Write to file… • Remove • Play Some functions act on only certain types of objects and in certain environments (e.g., Edit window). Naming conventions: - always begin with uppercase letters - may have spaces - functions that take arguments end in dots (…)

16. Elements in a script • Commands (specific to Praat scripting language) • form, endform • select • print • clearinfo • if, endif • for, endfor … Naming conventions: - start with lowercase letters - one word

17. Creating a Praat script from scratch • To create a new script:Praat | New script

18. History • Praat keeps track of what you do by hand • If you want to do something, but you’re not sure of the syntax, do : • in script window: Edit | Clear history • in objects window, select the object you want to work on and perform the operation. (Query | Get duration) • in script window(Edit | Paste history)

19. Open the script: Starter4.praat

20. Loops • Allow the same commands and functions to be executed over and over again (on a list of files, for example) • Created with:for, endforrepeat, until(and other pairs of commands)

21. Bug tracking • Error messages can be transparent… • But often are not! • Practice fixing errors by introducing them: – missing $, misspelled/wrong case variable, hard return in form, … • Use print command to print information to info window and find bugs. E.g.: • print got here 'newline$’ • print ‘baseFile’ 'newline$’ • Make changes and test incrementally • Save a backup script that works

22. Be (very!) careful… • … not to overwrite or delete important files! • Scripts are powerful and one mistake can wipe out days (weeks, months…) of work in seconds • Keep backups of data • When writing/adapting a new script, work in a temporary directory

23. Acknowledgments • Slides on element types based on Praat scripting tutorial basics, Florian Jaeger http://www.stanford.edu/~tiflo/teaching/tutorials/T_Jaeger_042104-praat%20scripting.htm#slide0001.htm

24. My new lab (as of October 1, 2008)Laboratoire Parole et LangageAix-en-Provence, France • My e-mail address will be:pauline.welby@lpl-aix.fr