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Reciprocal representation of duration

recip.Rd

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 selected field 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 (character)
#> [1] 4.  8   16  16  16  16  1%0 4  
recip(tokens, parse(grace = NA))
#> **recip (character)
#> [1] 4. 8  16 16 16 16 .  4 
recip(tokens, scale = 2)
#> **recip (character)
#> [1] 2.  4   8   8   8   8   1%0 2  

recip(c(.25, .25, .25, .25, .5, 1))
#> **recip (character)
#> [1] 4 4 4 4 2 1
recip(c(.25, .25, .25, .25, .5, 1), parse(unit = '4'))
#> **recip (character)
#> [1] 16 16 16 16 8  4 

B075 <- readHumdrum(humdrumRroot, "HumdrumData/BeethovenVariations/B075_00_05_a.krn")
#> Finding and reading files...
#> 	REpath-pattern '/home/nat/.tmp/RtmpBDgnJw/temp_libpath28db92437ebb13/humdrumR/HumdrumData/BeethovenVariations/B075_00_05_a.krn' matches 1 text files in 1 directory.
#> One file read from disk.
#> Validating one file...
#> all valid.
#> Parsing one file...
#> Assembling corpus...
#> Done!
within(B075, subset = Spine > 2,  recip(Token))
#> ###################### vvv B075_00_05_a.krn vvv ######################
#>    1:  !!!COM: Beethoven
#>    2:  !!!OTL: 7 Variations on a Quartet by Winter
#>    3:  !!!Variation: Theme e
#>    4:      ****recip    ****recip       ****recip           ****recip
#>    5:              .            .               .                   .
#>    6:              .            .               .                   .
#>    7:          *M2/4        *M2/4           *M2/4               *M2/4
#>    8:              .            .               .                   .
#>    9:          FALSE       FALSE4           TRUE4        TRUE TRUE4 4
#>   10:            =37          =37             =37                 =37
#>   11:          FALSE       FALSE2    TRUE TRUE2 2        TRUE TRUE8 8
#>   12:              .            .               .        TRUE TRUE8 8
#>   13:              .            .               .        TRUE TRUE8 8
#>   14:              .            .               .        TRUE TRUE8 8
#>   15:            =38          =38             =38                 =38
#>   16:              .            .               .    TRUE TRUE1%0 1%0
#>   17:          FALSE       FALSE4    TRUE TRUE4 4        TRUE TRUE4 4
#>   18:          FALSE       FALSE4    TRUE TRUE4 4        TRUE TRUE4 4
#>   19:            =39          =39             =39                 =39
#>   20:          FALSE       FALSE4    TRUE TRUE8 8        TRUE TRUE8 8
#>   21:              .            .    TRUE TRUE8 8        TRUE TRUE8 8
#>   22:          FALSE       FALSE4    TRUE TRUE8 8        TRUE TRUE8 8
#>   23:              .            .    TRUE TRUE8 8        TRUE TRUE8 8
#>   24:            =40          =40             =40                 =40
#>   25:          FALSE       FALSE2           TRUE4        TRUE TRUE4 4
#>   26:              .            .           TRUE4               TRUE4
#>   27:             *-           *-              *-                  *-
#> ###################### ^^^ B075_00_05_a.krn ^^^ ######################
#> 
#>    Data fields: 
#> 	         Token                   :: character
#> 	        *humdrumR:::recip(Token) :: character (**recip tokens)
#> 	        *subset                  :: logical
#> 

with(B075, subset = Spine > 2, recip(Token)) |> table()
#> 
#> 1%0   8   4   2   1 
#>   2  24  21   4   0