A .scl pitch is either in Cents or is a Ratio.

An enumeration type for .scl pitch classification.

A nearness value for deriving approximate rationals.

Derive Pitch_Type from Pitch.

Pitch as Cents, conversion by ratio_to_cents if necessary.

Pitch as Rational, conversion by reconstructed_ratio if necessary, hence epsilon.

A pair giving the number of Cents and number of Ratio pitches.

If scale is uniform, give type.

The predominant type of the pitches for Scale.

A scale has a name, a description, a degree, and a sequence of pitches. The name is the the file-name without the .scl suffix. By convention the first comment line gives the file name (with suffix). The pitches do NOT include 1:1 or 0c and do include the octave.

The name of a scale.

Text description of a scale.

The degree of the scale (number of Pitches).

The Pitches at Scale.

Is Pitch outside of the standard octave (ie. cents 0-1200 and ratios 1-2)

Ensure degree and number of pitches align.

Raise error if scale doesn't verify, else id.

The last Pitch element of the scale (ie. the octave). For empty scales give Nothing.

Error variant.

Is scale_octave perfect, ie. Ratio of 2 or Cents of 1200.

Are all pitches of the same type.

Are the pitches in ascending sequence.

Make scale pitches uniform, conforming to the most predominant pitch type.

Scale as list of Cents (ie. pitch_cents) with 0 prefix.

map round of scale_cents.

Scale as list of Rational (ie. pitch_ratio) with 1 prefix.

Require that Scale be uniformly of Ratios.

Erroring variant of 'scale_ratios_u.

Are scales equal (==) at degree and tuning data.

db <- scl_load_db
let r = [2187/2048,9/8,32/27,81/64,4/3,729/512,3/2,6561/4096,27/16,16/9,243/128,2/1]
let Just py = find (scale_eq ("","",length r,map Right r)) db
scale_name py == "pyth_12"

scale_eqv provides an approximate equality function.

let c = map T.ratio_to_cents r
let Just py' = find (scale_eqv 0.00001 ("","",length c,map Left c)) db
scale_name py' == "pyth_12"

Are scales equal at degree and intersect to at least k places of tuning data.

Is s1 a proper subset of s2.

Are scales equal at degree and equivalent to within epsilon at pitch_cents.

Comment lines begin with !.

Remove to end of line ! comments.

remove_eol_comments " 1 ! comment" == " 1 "

Remove comments and trailing comments (the description may be empty, keep nulls)

filter_comments ["!a","b","","c","d!e"] == ["b","","c","d"]

Pitches are either cents (with decimal point, possibly trailing) or ratios (with /).

map parse_pitch ["70.0","350.","3/2","2","2/1"] == [Left 70,Left 350,Right (3/2),Right 2,Right 2]

Pitch lines may contain commentary.

Parse .scl file.

Read the environment variable SCALA_SCL_DIR, which is a sequence of directories used to locate scala files on.

setEnv "SCALA_SCL_DIR" "/home/rohan/data/scala/90/scl"

Lookup the SCALA_SCL_DIR environment variable, which must exist, and derive the filepath. It is an error if the name has a file extension.

mapM scl_derive_filename ["young-lm_piano","et12"]

If the name is an absolute file path and has a .scl extension, then return it, else run scl_derive_filename.

scl_resolve_name "young-lm_piano"
scl_resolve_name "/home/rohan/data/scala/90/scl/young-lm_piano.scl"
scl_resolve_name "/home/rohan/data/scala/90/scl/unknown-tuning.scl"

Load .scl file, runs resolve_scl.

s <- scl_load "xenakis_chrom"
pitch_representations (scale_pitches s) == (6,1)
scale_ratios 1e-3 s == [1,21/20,29/23,179/134,280/187,11/7,100/53,2]

Load all .scl files at dir, associate with file-name.

db <- scl_load_dir_fn "/home/rohan/data/scala/91/scl"
length db == 5176 -- v.91
map (\(fn,s) -> (takeFileName fn,scale_name s)) db

snd of scl_load_dir_fn

Load Scala data base at scl_get_dir.

db <- scl_load_db
mapM_ (putStrLn . unlines . scale_stat) (filter (not . perfect_octave) db)

http://www.huygens-fokker.org/docs/scalesdir.txt

Format as CSV file.

db <- scl_load_db
writeFile "/tmp/scl.csv" (scales_dir_txt_csv db)

Simple plain-text display of scale data.

db <- scl_load_db
writeFile "/tmp/scl.txt" (unlines (intercalate [""] (map scale_stat db)))

Pretty print Pitch in Scala format.

Pretty print Scale in Scala format.

scl <- scl_load "et19"
scl <- scl_load "young-lm_piano"
putStr $ unlines $ scale_pp scl

Write scl to dir with the file-name scale_name.scl

scala distribution directory, given at SCALA_DIST_DIR.

setEnv "SCALA_DIST_DIR" "/home/rohan/opt/build/scala-22"

Load file from dist_get_dir.

fmap lines load_dist_file

s <- load_dist_file_ln "intnam.par"
length s == 565 -- Scala 2.46d

Is scale just-intonation (ie. are all pitches ratios)

Calculate limit for JI scale (ie. largest prime factor)

Sum of absolute differences to scale given in cents, sorted, with rotation.

Variant selecting only nearest and with post-processing function.

scl <- scl_load "holder"
scale_cents_i scl
c = [0,83,193,308,388,502,584,695,778,890,1004,1085,1200]
(_,r,_) = scl_cdiff_abs_sum_1 round c scl
r == [0,2,-1,1,0,-1,0,-1,0,0,0,0,0]

Sort DB into ascending order of sum of absolute of differences to scale given in cents. Scales are sorted and all rotations are considered.

db <- scl_load_db
c = [0,83,193,308,388,502,584,695,778,890,1004,1085,1200]
r = scl_db_query_cdiff_asc round db c
((_,dx,_),_):_ = r
dx == [0,2,-1,1,0,-1,0,-1,0,0,0,0,0]
mapM_ (putStrLn . unlines . scale_stat . snd) (take 10 r)

Is x the same scale as scl under cmp.

Find scale(s) that are scale_cmp_ji to x. Usual cmp are (==) and is_subset.

Translate Scale to Tuning. If Scale is uniformly rational, Tuning is rational, else it is in Cents.

Convert Tuning to Scale.

tuning_to_scale ("et12","12 tone equal temperament") (T.tn_equal_temperament 12)

scale_to_tuning of scl_load.

fmap T.tn_limit (scl_load_tuning "pyra") -- Just 59