phonfeatures

phonfeatures is an R package which allows user to efficiently add columns with articulatory features to existing data frames with phonetic characters using the function add_features().

The package provides several generic features for all regular IPA and X-SAMPA characters as well as for most diacritics. These generic features can be checked using the function feature_lookup(). The also provides functionality for changing the feature values of known characters with feature_reassign(), and for introducing unknown characters with feature_assign().

Installation

You can install the development version of phonfeatures from GitHub with:

# install.packages("devtools")
devtools::install_github("rpuggaardrode/phonfeatures")

Usage

Adding features to a data frame

The most common use case is when you have a data frame containing transcriptions, and you want to convert those transcriptions into some articulatory features. It could fx look like this:

library(phonfeatures)
head(test_data, 10)
#>    Identifier IntVocIntervals     tmin     tmax age Stop
#> 1           1               1 0.000000 0.245914  20    d
#> 2           2               2 0.245914 0.798165  20    k
#> 3           3               3 0.798165 1.103336  20    d
#> 4           4               4 1.103336 1.716694  20    k
#> 5           5               5 1.716694 2.206374  20    k
#> 6           6               6 2.206374 2.546418  20    g
#> 7           7               7 2.546418 2.844114  20    t
#> 8           8               8 2.844114 3.357136  20    k
#> 9           9               9 3.357136 3.962371  20    k
#> 10         10              10 3.962371 4.462383  20    k

Say you want to add columns to this data frame with information about place of articulation and laryngeal features corresponding to the stop column. You would proceed like this:

new_data <- add_features(data=test_data, col='Stop', feature=c('place', 'lar'))
head(new_data, 10)
#>    Identifier IntVocIntervals     tmin     tmax age Stop    place       lar
#> 1           1               1 0.000000 0.245914  20    d alveolar    voiced
#> 2           2               2 0.245914 0.798165  20    k    velar voiceless
#> 3           3               3 0.798165 1.103336  20    d alveolar    voiced
#> 4           4               4 1.103336 1.716694  20    k    velar voiceless
#> 5           5               5 1.716694 2.206374  20    k    velar voiceless
#> 6           6               6 2.206374 2.546418  20    g    velar    voiced
#> 7           7               7 2.546418 2.844114  20    t alveolar voiceless
#> 8           8               8 2.844114 3.357136  20    k    velar voiceless
#> 9           9               9 3.357136 3.962371  20    k    velar voiceless
#> 10         10              10 3.962371 4.462383  20    k    velar voiceless

Checking feature values

You can use ?add_features to see which features are generically available, or use feature_lookup() to check all the features that are generically assigned to a character:

feature_lookup(phon='g')
#>   height backness roundness place major_place manner major_manner    lar  voice
#> 8                           velar      dorsal   stop    obstruent voiced voiced
#>   length modifications syllabic  release nasalization tone
#> 8  short            NA       no released           no   NA

feature_lookup() can also be used to check specific feature values:

feature_lookup(phon='g', feature=c('lar', 'place'))
#>      lar place
#> 8 voiced velar

Changing feature values

The generic features will not be suitable for all purposes. For example, if (like me) you are interested in Danish stops, there’s a good chance that you have been using /b d g p t k/ as a shorthand for sounds that are not actually voiced and voiceless, but rather voiceless and aspirated.

The package also provides functions for creating a new lookup table used for checking feature values. We can update the value of lar for /b d g/ with the function feature_reassign() and save it to a new data frame dan_lkup like this:

dan_lkup <- feature_reassign(sampa=c('b', 'd', 'g'), 
                             feature='lar', val='voiceless')

And the values of /p t k/ can then be updated by running feature_reassign() again, this time specifying that we’re using the lookup table dan_lkup:

dan_lkup <- feature_reassign(sampa=c('p', 't', 'k'), 
                             feature='lar', val='aspirated',
                             lookup=dan_lkup)

We can now use dan_lkup to add features to our data frame, instead of using the generic features:

new_data <- add_features(data=test_data, col='Stop', feature=c('place', 'lar'),
                         lookup=dan_lkup)
head(new_data, 10)
#>    Identifier IntVocIntervals     tmin     tmax age Stop    place       lar
#> 1           1               1 0.000000 0.245914  20    d alveolar voiceless
#> 2           2               2 0.245914 0.798165  20    k    velar aspirated
#> 3           3               3 0.798165 1.103336  20    d alveolar voiceless
#> 4           4               4 1.103336 1.716694  20    k    velar aspirated
#> 5           5               5 1.716694 2.206374  20    k    velar aspirated
#> 6           6               6 2.206374 2.546418  20    g    velar voiceless
#> 7           7               7 2.546418 2.844114  20    t alveolar aspirated
#> 8           8               8 2.844114 3.357136  20    k    velar aspirated
#> 9           9               9 3.357136 3.962371  20    k    velar aspirated
#> 10         10              10 3.962371 4.462383  20    k    velar aspirated

IPA and X-SAMPA

You may have noticed that the phonetic character argument in feature_reassign() is called sampa. This is because this function only works with X-SAMPA characters. add_features() and feature_lookup() also use X-SAMPA characters by default, but these functions have an option to use IPA instead, by setting ipa=TRUE. Let’s see what this does to the code we just ran:

new_data <- add_features(data=test_data, col='Stop', feature=c('place', 'lar'),
                         lookup=dan_lkup, ipa=TRUE)
head(new_data, 10)
#>    Identifier IntVocIntervals     tmin     tmax age Stop    place       lar
#> 1           1               1 0.000000 0.245914  20    d alveolar voiceless
#> 2           2               2 0.245914 0.798165  20    k    velar aspirated
#> 3           3               3 0.798165 1.103336  20    d alveolar voiceless
#> 4           4               4 1.103336 1.716694  20    k    velar aspirated
#> 5           5               5 1.716694 2.206374  20    k    velar aspirated
#> 6           6               6 2.206374 2.546418  20    g    velar voiceless
#> 7           7               7 2.546418 2.844114  20    t alveolar aspirated
#> 8           8               8 2.844114 3.357136  20    k    velar aspirated
#> 9           9               9 3.357136 3.962371  20    k    velar aspirated
#> 10         10              10 3.962371 4.462383  20    k    velar aspirated

It makes no difference of course! /b d g p t k/ are identical in IPA and X-SAMPA. But this is what happens when feature_lookup() is used with an IPA character which doesn’t exist as an X-SAMPA character.

feature_lookup(phon='ø', feature='length')
#> Error in feature_lookup(phon = "ø", feature = "length"): I am unfamiliar with ø
#>  Definitions for unknown characters can be added with the feature_assign() function.

The function throws a warning saying that the character is unknown. Let’s try again with ipa=TRUE:

feature_lookup(phon='ø', feature='length', ipa=TRUE)
#> [1] "short"

Say you have a data frame with IPA characters, and the sound /ø/ is always long in the language, so you want to change the length value to long. feature_reassign() only accepts X-SAMPA characters, but fear not! The function ipa::ipa() is used under the hood to convert IPA characters to X-SAMPA characters, so you can simply reassign the corresponding X-SAMPA character (in this case 2):

lkup <- feature_reassign(sampa='2', feature='length', val='long')
feature_lookup(phon='ø', feature='length', lookup=lkup, ipa=TRUE)
#> [1] "long"

Adding new characters

You may want to use add_features() with a data frame where, for one reason or another, you have been using non-standard symbols. For example, you’ve been using ph instead of the standard X-SAMPA p_h to indicate an aspirated bilabial stop. In this case, feature_lookup() will shoot you an error:

feature_lookup(phon='ph')
#> Error in feature_lookup(phon = "ph"): I am unfamiliar with ph
#>  Definitions for unknown characters can be added with the feature_assign() function.

Again, fear not! The feature_assign function can help with creating a customized lookup table with new characters. This feature also allows you to copy the features from a known character, or a character with known diacritics, using the copy argument. For our ph case, you would do the following:

lkup <- feature_assign(new='ph', copy='p_h')
feature_lookup(phon='ph', lookup=lkup)
#>     height backness roundness    place major_place manner major_manner
#> 103                           bilabial      labial   stop    obstruent
#>           lar     voice length modifications syllabic  release nasalization
#> 103 aspirated voiceless  short            NA       no released           no
#>     tone
#> 103   NA

feature_assign also allows you to build your own feature sets from scratch:

lkup <- feature_assign(new='kh',
                       feature=c('place', 'manner', 'lar'),
                       val=c('velar', 'stop', 'aspirated'))
feature_lookup(phon='kh', lookup=lkup)
#>     height backness roundness place major_place manner major_manner       lar
#> 103   <NA>     <NA>      <NA> velar        <NA>   stop         <NA> aspirated
#>     voice length modifications syllabic release nasalization tone
#> 103  <NA>   <NA>            NA     <NA>    <NA>         <NA>   NA

Or you can copy a known character and change some of the features (say, if you’ve been using th to refer to a long, dental aspirated stop):

lkup <- feature_assign(new='th',
                       feature=c('place', 'length'),
                       val=c('dental', 'long'),
                       copy='t_h')
feature_lookup(phon='th', lookup=lkup)
#>     height backness roundness  place major_place manner major_manner       lar
#> 103                           dental     coronal   stop    obstruent aspirated
#>         voice length modifications syllabic  release nasalization tone
#> 103 voiceless   long            NA       no released           no   NA

Unfortunately, feature_assign does not at present allow you to add unknown IPA characters.

Contact

If you run into any problems using phonfeatures, feel free to leave a bug report on GitHub or reach out at r.puggaard at phonetik.uni-muenchen.de

NewDanishPhonetics / phonfeatures-R-package