FoscMeter

Returns a FoscMeter.

Description

FoscMeter

Meter models a common practice understanding of beats and other levels of rhythmic organization structured as a tree. Meter structure corresponds to the monotonically increasing sequence of factors in the numerator of a given time signature. Successively deeper levels of the tree divide time by successive factors.

Attributes Summary

Class Methods

Instance Properties

Instance Methods: Special Methods

Instance Methods

Usage

1. Example

   FoscMeter(FoscTimeSignature([5, 4])).inspect;

   FoscMeter.new

2. Example

   FoscMeter(FoscDuration(5, 4)).inspect;

   FoscMeter.new

3. Example

   FoscMeter(FoscFraction(5, 4)).inspect;

   FoscMeter.new

4. Example

   FoscMeter([5, 4]).inspect;

   FoscMeter.new

5. Example

   FoscMeter(FoscRhythm([5, 4], [2, 3])).inspect;

   FoscMeter.new

6. Example

   FoscMeter(FoscRhythm([5, 4], [1, [7, [3, 2, 2]], 2])).inspect;

   FoscMeter.new

7. Example

   FoscMeter([5, 4], increaseMonotonic: true).inspect;

   FoscMeter.new

8. Example

   a = FoscMeter([5,4]);
   a.inspect;

   FoscMeter.new

   a.increaseMonotonic;

   false

   a.denominator;

   4

   a.numerator;

   5

   a.preferredBoundaryDepth.isNil;

   true

   a.rootNode;

   FoscRhythm.new

Class Methods

fitMeters

Finds the best-matching sequence of meters for the offsets contained in argument.

Coerces offsets from argument via MetricAccentKernel.count_offsets().

Coerces Meters from meters via MeterList.

Returns array.

Instance Properties

decreaseDurationsMonotonically

Is true when meter divides large primes into collections of 2 and 3 that decrease monotonically. Otherwise false.

1. Example

   FoscMeter([7, 8], decreaseDurationsMonotonically: true).inspect;
   FoscMeter([7, 8], decreaseDurationsMonotonically: false).inspect;

   FoscMeter.new

denominator

Gets denominator of meter.

1. Example

   FoscMeter([7, 8]).denominator;

   8

depthwiseOffsetInventory

Gets depthwise offset inventory of meter.

Returns array.

1. Example

   a = FoscMeter([7, 4]);
   a.depthwiseOffsetInventory.do { |offsets, i|
       Post << i << nl;
       offsets.do { |each| Post.space << each.pair << nl };
   };

duration

Gets duration of meter.

1. Example

   m = FoscMeter([7, 4]);
   m.duration.inspect;

   ObjectInspector.new

impliedTimeSignature

Gets implied time signature of meter.

1. Example

   m = FoscMeter([4, 4]);
   m.impliedTimeSignature.inspect;

   FoscTimeSignature.new

isCompound

Is true when meter is compound.

Compound meters are defined as those equal with a numerator divisible by 3 but not equal 3.

1. Example

   FoscMeter([3, 4]).isCompound;

   false

   FoscMeter([4, 8]).isCompound;

   false

   FoscMeter([6, 8]).isCompound;

   true

   FoscMeter([15, 32]).isCompound;

   true

isSimple

Is true when meter is simple. Otherwise false.

Simple meters are defined as those equal with a numerator not divisible by 3.

Meters with numerator equal to 3 are also defined as simple.

1. Example

   FoscMeter([3, 4]).isSimple;

   true

   FoscMeter([4, 8]).isSimple;

   true

   FoscMeter([6, 8]).isSimple;

   false

   FoscMeter([15, 32]).isSimple;

   false

numerator

Gets numerator of meter.

Returns positive integer.

1. Example

   m = FoscMeter([7, 4]);
   m.numerator;

   7

pair

Gets numerator and denominator pair.

1. Example

   FoscMeter([7, 8]).pair;

   [ 7, 8 ]

preferredBoundaryDepth

Gets preferred boundary depth of meter. Used by rewriteMeter method.

Returns integer or nil.

1. Example

   m = FoscMeter([4, 4]);
   m.preferredBoundaryDepth;

2. Example

   m = FoscMeter([4, 4], preferredBoundaryDepth: 2);
   m.preferredBoundaryDepth;

   2

rootNode

Gets root node of meter.

Returns rhythm tree node.

1. Example

   m = FoscMeter([7, 4]);
   m.rootNode;

   FoscRhythm.new

Instance Methods: Special Methods

==

Is true when argument is a meter with an rtm format equal to that of this meter. Otherwise false.

Returns true or false.

format

Formats meter.

Returns string.

1. Gets storage format of 7/4:

   a = FoscMeter(#[7,4]);
   a.format;

   7/4

hash

Hashes meter.

Returns integer.

inspect

1. Example

   a = FoscMeter(#[7,4]);
   a.inspect;

   FoscMeter.new

2. Example

   a = FoscMeter(#[7,4], increaseMonotonic: true);
   a.inspect;

   FoscMeter.new

iter

Iterates meter.

Yields pairs.

str

!!!TODO: make identical to abjad.

Gets string representation of meter.

Returns string.

1. Example

   FoscMeter([7, 4]).str;

   7/4

Instance Methods

generateOffsetKernelToDenominator

Generates a dictionary of all offsets in a meter up to denominator.

Keys are the offsets and the values are the normalized weights of those offsets.

This is useful for testing how strongly a collection of offsets responds to a given meter.

Returns dictionary.