undefined

When you give a query command for a numeric value, Praat sometimes writes the numeric value --undefined-- into the Info window (two hyphens at both sides of the word). This happens if the value you ask for is not defined, as in the following examples:

Usage in a script

In a Praat script, this value is simply represented as "undefined". You use it to test whether a query command returned a valid number:

select Pitch hallo
meanPitch = Get mean... 0.1 0.2 Hertz Parabolic
if meanPitch = undefined
    # Take some exceptional action.
else
    # Take the normal action.
endif

Details for hackers

In text files, this value is written as --undefined--. In binary files, it is written as a big-endian IEEE positive infinity. In memory, it is the ANSI-C constant HUGE_VAL, which equals infinity on IEEE machines.

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© ppgb, April 14, 2004