tsym {musicMCT} | R Documentation |
Test for transpositional symmetry
Description
Does the set map onto itself at some transposition other than T_0
? That is,
does it map onto itself under T_n
for some appropriate n
? tsym()
can return either TRUE
/FALSE
or an index of symmetry but defaults to the former.
tsym_index()
is a simple wrapper for tsym()
that returns the latter. tsym_degree()
counts the total number of transpositional symmetries.
Usage
tsym(set, return_index = FALSE, edo = 12, rounder = 10)
tsym_index(set, ...)
tsym_degree(set, ...)
Arguments
set |
Numeric vector of pitch-classes in the set |
return_index |
Should the function return a specific index at which
the set is symmetrical? Defaults to |
edo |
Number of unit steps in an octave. Defaults to |
rounder |
Numeric (expected integer), defaults to |
... |
Arguments to be passed to |
Value
By default, tsym()
returns TRUE
if the set has non-trivial transpositional
symmetry, FALSE
otherwise. If return_index
is TRUE
, returns a vector of transposition
levels at which the set is symmetric, including 0
. tsym_index()
is a wrapper for tsym()
which sets return_index
to TRUE
. tsym_degree()
gives the degree of symmetry, which
is simply the length of tsym_index()
's value.
Examples
tsym(sc(6, 34))
tsym(sc(6, 35))
tsym(edoo(5))
# Works for continuous values:
tsym(tc(j(dia), edoo(3)))
# Index and Degree:
tsym_index(c(0, 1, 3, 6, 7, 9))
tsym_degree(edoo(7))