Rank and codimension: Difference between revisions
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The '''rank''' of a [[Regular_Temperaments|regular temperament]] is the number of independent intervals, called ''generators'', which can be combined together to obtain any interval of the temperament. For instance, every interval of [[Meantone|meantone]] can be obtained as a combination of a certain number of octaves up or down, plus a certain number of flattened meantone fifths up or down. The terminology originally comes from group theory and linear algebra, although we are using the term "co-rank" slightly differently here. | The '''rank''' of a [[Regular_Temperaments|regular temperament]] is simply its dimension. Mathematically, it is the number of independent intervals, called ''generators'', which can be combined together to obtain any interval of the temperament. For instance, every interval of [[Meantone|meantone]] can be obtained as a combination of a certain number of octaves up or down, plus a certain number of flattened meantone fifths up or down. The terminology originally comes from group theory and linear algebra, although we are using the term "co-rank" slightly differently here. | ||
In the parlance of group theory, the intervals of a regular temperament comprise a [http://en.wikipedia.org/wiki/Free_abelian_group#Rank finitely generated free abelian group] with a rank equal to the number of generators. In the parlance of linear algebra, the rank of the temperament is also the rank of any mapping matrix defining the temperament. | In the parlance of group theory, the intervals of a regular temperament comprise a [http://en.wikipedia.org/wiki/Free_abelian_group#Rank finitely generated free abelian group] with a rank equal to the number of generators. In the parlance of linear algebra, the rank of the temperament is also the rank of any mapping matrix defining the temperament. | ||