soundgen (version 1.1.1)

wiggleAnchors: Randomly modify anchors

Description

Internal soundgen function.

Usage

wiggleAnchors(df, temperature, temp_coef, low, high, wiggleAllRows = FALSE,
  invalidArgAction = c("adjust", "abort", "ignore")[1])

Arguments

df

dataframe of anchors, for ex. data.frame(time = c(0, .1, .8, 1), value = c(100, 230, 180, 90))

temperature, temp_coef

regulate the amount of stochasticity ("wiggling"). Since temperature is used in several functions, temp_coef gives more flexibility by controlling how much temperature affects this particular aspect, namely random variation in anchors. These two are multiplied, so temp_coef of 0.5 halves the effect of temperature.

low, high

bounds on possible variation. Both low and high should be vectors of length 2: the first element specifies the boundary for df$time and the second for df$value. Ex.: low = c(0,1) - low bound on "time"=0, low bound on "value"=1

wiggleAllRows

should the first and last time anchors be wiggled? (TRUE for breathing, FALSE for other anchors)

invalidArgAction

what to do if an argument is invalid or outside the range in permittedValues: 'adjust' = reset to default value, 'abort' = stop execution, 'ignore' = throw a warning and continue (may crash)

Value

Modified original dataframe.

Details

A helper function for introducing random variation into any anchors (for pitch / breathing / amplitude / ...). At higher temperatures can also add or delete an anchor. NB: make sure the lower and upper bounds are reasonable given the scale of df$value!

Examples

# NOT RUN {
soundgen:::wiggleAnchors(df = data.frame(
  time = c(0, .1, .8, 1), value = c(100, 230, 180, 90)),
  temperature = .2, temp_coef = .1, low = c(0, 50), high = c(1, 1000),
  wiggleAllRows = FALSE) # pitch
soundgen:::wiggleAnchors(df = data.frame(time = 0, value = 240),
  temperature = .2, temp_coef = .1, low = c(0, 50), high = c(1, 1000),
  wiggleAllRows = FALSE) # pitch, sinle anchor
soundgen:::wiggleAnchors(df = data.frame(
  time = c(-100, 100, 600, 900), value = c(-120, -80, 0, -120)),
  temperature = .4, temp_coef = .5, low = c(-Inf, -120), high = c(+Inf, 30),
  wiggleAllRows = TRUE) # noise
# formants
formants = list(f1 = list(time = 0, freq = 860, amp = 30, width = 120),
                f2 = list(time = c(0,1), freq = 1280,
                amp = c(10,40), width = 120))
for (f in 1:length(formants)) {
  formants[[f]] = soundgen:::wiggleAnchors(
    df = formants[[f]],
    temperature = .4, temp_coef = .5,
    low = c(0, 50, 0, 1),
    high = c(1, 8000, 120, 2000),
    wiggleAllRows = FALSE
  )
}
print(formants)
# }