norm_dct_wattfab {tidynorm} | R Documentation |
Watt and Fabricius DCT normalization
Description
Watt and Fabricius DCT normalization
Usage
norm_dct_wattfab(
.data,
...,
.token_id_col,
.by = NULL,
.param_col = NULL,
.drop_orig = FALSE,
.names = "{.formant}_wf",
.silent = FALSE
)
Arguments
.data |
A data frame containing vowel formant data |
... |
|
.token_id_col |
|
.by |
|
.param_col |
A column identifying the DCT parameter number. |
.drop_orig |
Should the originally targeted columns be dropped. |
.names |
A |
.silent |
Whether or not the informational message should be printed. |
Details
This is a modified version of the Watt & Fabricius Method. The original method identified point vowels over which F1 and F2 centroids were calculated. The procedure here just identifies centroids by taking the mean of all formant values.
\hat{F}_{ij} = \frac{F_{ij}}{S_i}
S_i = \frac{1}{N}\sum_{j=1}^N F_{ij}
Where
-
\hat{F}
is the normalized formant -
i
is the formant number -
j
is the token number
Value
A data frame of Watt & Fabricius normalized DCT coefficients.
References
Watt, D., & Fabricius, A. (2002). Evaluation of a technique for improving the mapping of multiple speakers’ vowel spaces in the F1 ~ F2 plane. Leeds Working Papers in Linguistics and Phonetics, 9, 159–173.
Examples
library(tidynorm)
library(dplyr)
ggplot2_inst <- require(ggplot2)
speaker_dct <- speaker_tracks |>
reframe_with_dct(
F1:F3,
.by = speaker,
.token_id_col = id,
.time_col = t
)
# Normalize DCT coefficients
speaker_dct_norm <- speaker_dct |>
norm_dct_wattfab(
F1:F3,
.by = speaker,
.token_id_col = id,
.param_col = .param
)
# Apply average and apply inverse dct
# to plot tracks
track_norm_means <- speaker_dct_norm |>
summarise(
.by = c(speaker, vowel, .param),
across(
ends_with("_wf"),
mean
)
) |>
reframe_with_idct(
ends_with("_wf"),
.by = speaker,
.token_id_col = vowel,
.param_col = .param
)
if (ggplot2_inst) {
track_norm_means |>
ggplot(
aes(F2_wf, F1_wf, color = speaker)
) +
geom_path(
aes(
group = interaction(speaker, vowel)
)
) +
scale_x_reverse() +
scale_y_reverse() +
scale_color_brewer(palette = "Dark2") +
coord_fixed()
}