- 162 -Mazzola, Guerino / Noll, Thomas / Lluis-Puebla, Emilio: Perspectives in Mathematical and Computational Music Theory 
  Erste Seite (1) Vorherige Seite (161)Nächste Seite (163) Letzte Seite (454)      Suchen  Nur aktuelle Seite durchsuchen Gesamtes Dokument durchsuchen     Aktuelle Seite drucken Hilfe 


 | t --n-|((n2/t)-)--------------------------Mc- 12 |(63) 44 |(44) 499 |(36) 1306 |(2 )2 902 24 |(123 ) 56450 |(84) 65735799 |(66) 4008.268588 |(48) 187886.308429 |(31)2 381736.855102 |(2 2) 13176.573910 36 |(183) 126047906 |(124 ) 15.670055.601970 |(96) 24829.574426.591236 |(69) 103.016116.387908.956698 |(41)2 10778.751016.666506.604919 |(318) 9910.160306.188702.944292 |(2 2) 6.156752.656678.674792 40 |(204) 1723.097066 |(105 ) 4.901417.574950.588294 |(88) 1595.148844.422078.211829 |(51)0 11.765613.697294.131102.617360 |(420) 88.656304.986604.408738.684375 (2 ) 7995.774669.504366.055054


Table 1: Number of mosaics in Z n of block-type ((n/t)t) .

However, the description of the isomorphism classes of canons as pairs (L,Cn(A)) consisting of Lyndon words L and Cn -orbits of subsets A of Zn with some additional properties (c.f. Lemma 7) can also be used for the determination of complete sets of representatives of non-isomorphic canons in Zn , as was indicated in the last part of Fripertinger (2002). These methods belong to step 3 of the general classification. There exist fast algorithms for computing all Lyndon words of length n over {0,1} and all Cn -orbit representatives of subsets of Zn . For finding rhythmic tiling canons with t voices (where t is necessarily a divisor of n ), we can restrict ourselves to Lyndon words L with exactly n/t entries 1 and to representatives A0 of the Cn -orbits of t -subsets of Zn . Then each pair (L,A0) must be tested whether it is a regular tiling canon. In this test we only have to test whether the voices described by (L,A0) determine a partition on Zn , because in this case it is obvious that (L,A0) does not satisfy the assumptions of Lemma 7.

For finding the number of rhythmic tiling canons, we make use of still another result concerning regular complementary canons of maximal category. First we realize that (L,A0) is a tiling canon if and only if Zn is the direct sum L o+ A0 , i.e. Zn = L+ A0 and |Zn|= |L|.|A0 | . In other words, for each element x (- Zn there exists exactly one pair (x1,x2) (- L × A0 such that x = x1 + x2 .


Erste Seite (1) Vorherige Seite (161)Nächste Seite (163) Letzte Seite (454)      Suchen  Nur aktuelle Seite durchsuchen Gesamtes Dokument durchsuchen     Aktuelle Seite drucken Hilfe 
- 162 -Mazzola, Guerino / Noll, Thomas / Lluis-Puebla, Emilio: Perspectives in Mathematical and Computational Music Theory