Defining measurement point heuristics

A heuristic file is a yaml file with the following format:

yaml

heuristic: default
default:
    prop_time: "1/3"
specifics: []

• The heuristic field gives a name to the heuristic.
• The default field defines the default measurement point method.
• The specifics field defines specific rules for specific vowels.

The yaml file above, in fact, is the same as the default heuristic if none are provided.

Specifics

Let’s say you wanted to define a special measurement point rule for just the vowel /ay/, to measure it at maximum F1. This can be done by adding the following rule to the specifics list.

yaml

heuristic: ay-rule
default:
    prop_time: "1/3"
specifics:
    - label: ay
      prop_time: f1.max.prop_time

What this says is:

• Apply a special measurement point rule when the interval label is “ay”.
• Get the measurement point where the vowel’s prop_time is equal to the prop_time of F1 maximum.

Valid point expressions

The expression f1.max.prop_time defines the proportional time of F1 maximum. An entire point expression will always be of the format:

formant.anchor.time

Valid values for each slot are:

• Formants
  • f1, f2, f3, …
  • Any formant that’s available
• Anchor
  • min
  • max
• Time
  • time
  • rel_time
  • prop_time

Additionally, any other mathematical expression can be included. For example, the original FAVE suite had a measurement point heuristic for /aw/ and /ow/ defined in the docs as:

# - OW, AW measured halfway between beginning of segment and F1 maximum  ##

The heuristic file for this would look like:

yaml

heuristic: aw-ow-rule
default:
    prop_time: "1/3"
specifics:
    - label: aw
      prop_time: f1.max.prop_time / 2
    - label: ow
      prop_time: f1.max.prop_time / 2