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:

  • You select a Sound with a finishing time of 1.0 seconds and ask for the minimum point in the wave form between 1.5 and 2.0 seconds (with the query command Get minimum...).
  • You ask for a pitch value in a voiceless part of the sound (select a Pitch, then choose Get value at time...).
  • You type into the Calculator the following formula: 10^400.

## 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:

`selectObject: "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 usually a specific "not-a-number" (NaN), namely the result of dividing 0 by 0, although other NaNs, and also infinities, will equally be reported as --undefined--.

### Links to this page

- Formant: Get bandwidth at time...
- Formant: Get time of maximum...
- Formant: Get time of minimum...
- Formant: Get value at time...
- Formulas 4. Constants
- Get high index from time...
- Get low index from time...
- Get nearest index from time...
- Harmonicity: Get mean...
- Harmonicity: Get value at time...
- Harmonicity: Get value in frame...
- PointProcess: Get interval...
- PointProcess: Get jitter (ddp)...
- PointProcess: Get jitter (local)...
- PointProcess: Get jitter (local, absolute)...
- PointProcess: Get jitter (ppq5)...
- PointProcess: Get jitter (rap)...
- Sound: Get nearest zero crossing...
- Sound: Get standard deviation...
- Sound: Get value at sample number...