When working with sets in continuous pitch-class spaces (i.e., where
octave equivalence is needed), R's normal operator for modulo division
%% does not always give ideal results. Values that are very close to
(but below) the octave appear to be far from 0. This function uses
rounding to give octave-equivalent results that music theorists expect.
Usage
fpmod(set, edo = 12, rounder = 10)
Arguments
- set
Numeric vector of pitch-classes in the set
- edo
Number of unit steps in an octave. Defaults to 12.
- rounder
Numeric (expected integer), defaults to 10:
number of decimal places to round to when testing for equality.
Value
Numeric vector the same length as set
Examples
really_small <- 1e-13
c_major <- c(0, 4, 7, 12-really_small)
c_major %% 12
#> [1] 0 4 7 12
fpmod(c_major, 12)
#> [1] 0 4 7 0
