tidynorm (version 0.4.0)

norm_deltaF: Delta F Normalize

Description

Delta F Normalize

Usage

norm_deltaF(
  .data,
  ...,
  .by = NULL,
  .by_formant = FALSE,
  .drop_orig = FALSE,
  .keep_params = FALSE,
  .names = "{.formant}_df",
  .silent = opt("tidynorm.silent")
)

Value

A data frame of Delta F normalized formant values.

Arguments

.data

A data frame containing vowel formant data

...

<tidy-select> One or more unquoted expressions separated by commas. These should target the vowel formant data columns.

.by

<tidy-select> A selection of columns to group by. Typically a column of speaker IDs.

.by_formant

Ignored by this procedure

.drop_orig

Whether or not to drop the original formant data columns.

.keep_params

Whether or not to keep the Location (*_.L) and Scale (*_.S) normalization parameters

.names

A glue::glue() expression for naming the normalized data columns. The "{.formant}" portion corresponds to the name of the original formant columns.

.silent

Suppress normalization information messages when running a norm_*() function. (Defaults to FALSE, overwritable using option 'tidynorm.silent' or environment variable 'R_TIDYNORM_TIDYNORM_SILENT')

Details

$$ \hat{F}_{ij} = \frac{F_{ij}}{S} $$ $$ S = \frac{1}{MN}\sum_{i=1}^M\sum_{j=1}^N \frac{F_{ij}}{i-0.5} $$

Where

• \(\hat{F}\) is the normalized formant

• \(i\) is the formant number

• \(j\) is the token number

References

Johnson, K. (2020). The \(\Delta\)F method of vocal tract length normalization for vowels. Laboratory Phonology: Journal of the Association for Laboratory Phonology, 11(1), Article 1. tools:::Rd_expr_doi("10.5334/labphon.196")

Examples

library(tidynorm)
ggplot2_inst <- require(ggplot2)

speaker_data_deltaF <- speaker_data |>
  norm_deltaF(
    F1:F3,
    .by = speaker,
    .names = "{.formant}_df"
  )

if (ggplot2_inst) {
  ggplot(
    speaker_data_deltaF,
    aes(
      F2_df,
      F1_df,
      color = speaker
    )
  ) +
    stat_density_2d(
      bins = 4
    ) +
    scale_color_brewer(
      palette = "Dark2"
    ) +
    scale_x_reverse() +
    scale_y_reverse() +
    coord_fixed()
}