recip: Reciprocal representation of duration

In Computational-Cognitive-Musicology-Lab/humdrumR: humdrumR

Reciprocal representation of duration

Description

The standard approach to representing conventional note values in humdrum is the "reciprocal" **recip. Representation. The ⁠**recip⁠ rhythmic values are often used as a part of ⁠**kern⁠ representation, which also includes pitch information and notation details.

If recip() is applied to a humdrumR data class you may use the data's fields as arguments. If no field names are specified, the first selectedField is used as x.

Usage

## Default S3 method:
recip(
  x,
  ...,
  sep = "%",
  parseArgs = list(),
  scale = 1,
  unit = 1,
  inPlace = FALSE
)

## humdrumR S3 method:
humData |> select(Token) |> recip() 
humData |> recip(simple = TRUE)
humData |> recip(Token, Key = Key)

recip(
  x,
  ...,
  sep = "%",
  parseArgs = list(),
  scale = 1,
  unit = 1,
  inPlace = FALSE
)

Arguments

x	An input vector. The x argument can be any (atomic) vector, or a rational (rhythmInterval), or NULL. Must be parsable as rhythm infromation.
...	Arguments passed to the rhythm parser. There are also two hidden (advanced) arguments you can specify: memoize and deparse (see the details below).
sep	The separator printed between numerator and denominator. A single character string. Must be a single character string.
scale	A numeric or rational value which is used as the output unit of measurement. Defaults to rational(1, 1). Must be numeric or rational.
inPlace	Should non-rhythm information be retained in the output string? Defaults to FALSE. Must be a singleton logical value: an on/off switch. Defaults to FALSE. A singleton logical value, or NA. See "Grace notes" section below.

Details

⁠**recip⁠ values are literally the reciprocal of a duration value. Since most note values in conventional music notation are simple fractions the reciprocal approach is highly concise and very similar to conventional western notation and terminology. A "quarter note" is represented as the reciprocal of 1/4: simply "4". Full reciprocal fractions can be specified: "2%3" to indicate 3/2. The ⁠%⁠ separator can be changed using the sep argument.

As in conventional note values, "dots" can be added after a value to increase the duration by the ratio of (2 - (2^{-n})), where n is the number of dots. (One dot is 3/2; two dots is 7/4; etc.).

See Also

To better understand how this function works, read about the family of rhythm functions, or how rhythms are parsed and deparsed.

Other rhythm functions: duration(), grid(), notehead()

Examples

tokens <- c('4.GG', '8G', '16E', '16F#', '16G', '16D', 'q8D#', '4E')

recip(tokens)
recip(tokens, parse(grace = NA))
recip(tokens, scale = 2)

recip(c(.25, .25, .25, .25, .5, 1))
recip(c(.25, .25, .25, .25, .5, 1), parse(unit = '4'))

## Not run: 
B075 <- readHumdrum(humdrumRroot, "HumdrumData/BeethovenVariations/B075_00_05_a.krn")
within(B075, subset = Spine > 2,  recip(Token))

with(B075, subset = Spine > 2, recip(Token)) |> table()

## End(Not run)

Computational-Cognitive-Musicology-Lab/humdrumR documentation built on Oct. 22, 2024, 9:28 a.m.