Praat scripting basics

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Praat scripting basics

• Pauline Welby
• Coláiste na Tríonóide, Baile Átha Cliath
• (Irlanda)
• welbyp_at_tcd.ie

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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

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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

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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

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Detailed Praat scripting tutorial

• Available on the web (Praat web page)
• http//www.fon.hum.uva.nl/praat/manual/Scripting.h
  tml
• or
• From within Praat
• In objects window
• Help Praat intro
• Search scripting

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Keep in mind

• Its easier to adapt an existing script (your own
  or someone elses) 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/st
  cg/E
• (Cedric Gendrot, in French)
• http//www.helsinki.fi/lennes/praat-scripts(Miet
  ta Lennes, in English)
• http//www.icp.inpg.fr/7Eloeven/ScriptsPraat.html
  (Hélène Loevenbruck, in French)
• http//www.cphling.dk/pers/johtnd/praat/my_praat.h
  tm(John Tøndering, in English)
• http//www.ling.ohio-state.edu/kyoon/scripts/praa
  t(Kyuchul Yoon, in English)
• Also, try a Google search.

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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)

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Lets 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

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• Open the script
• Starter1.praat

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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

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Elements in a script

• Objects (are manipulated)
• everything in object window (at left)
• files
• numbers
• strings (letters, etc.)

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• Open the script
• Starter2.praat

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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

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• Open the script
• Starter3.praat

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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
  ()

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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

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Creating a Praat script from scratch

• To create a new scriptPraat New script

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History

• Praat keeps track of what you do by hand
• If you want to do something, but youre 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)

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• Open the script
• Starter4.praat

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Loops

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

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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

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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

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Acknowledgments

• Slides on element types based on Praat scripting
  tutorial basics, Florian Jaeger
• http//www.stanford.edu/tiflo/teaching/tutorials
  /T_Jaeger_042104-praat20scripting.htmslide0001.h
  tm

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• My new lab (as of October 1, 2008)Laboratoire
  Parole et LangageAix-en-Provence, France
• My e-mail address will bepauline.welby_at_lpl-aix.f
  r