Class: MM::Space

Inherits:
Object
  • Object
show all
Defined in:
lib/mm/space.rb

Constant Summary collapse

VERSION = 
"1.0.0"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(metric, opts = {}) ⇒ Space

Initialization method for MM::Space

metric - Array of MM::Metrics, where each metric corresponds to a dimension

in the MM::Space.

opts - Hash with additional parameters. (default: {})

:delta - The delta of the MM::Search function used in #morph.
  (default: 0.001)
:boundaries - Array of same size as metric containing pairs [low,
  high], which should be the bounding vectors of a given MM::Space.
:adjacent_points_function - Proc to use as the
  adjacent_points_function for MM::Search in #morph.
:cost_function - Proc to use for cost_function for MM::Search in
  #morph.

Returns an MM::Space object



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# File 'lib/mm/space.rb', line 25

def initialize metric, opts = {}
  @metric = metric
  @search_klass = opts[:search_klass] || MM::Search
  @delta = opts[:delta] || 0.001
  @boundaries = opts[:boundaries]
  @adjacent_points_function = opts[:adjacent_points_function]
  @cost_function = opts[:cost_function]
end

Instance Attribute Details

#adjacent_points_function ⇒ Object

Default adjacent_points_function. It takes all repeated permutations of a given morph.

Returns the adjacent_points_function Proc.



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# File 'lib/mm/space.rb', line 107

def adjacent_points_function
  @adjacent_points_function ||
  ->(current_point) {
    current_point.repeated_permutation(current_point.size)
  }
end

#boundaries ⇒ Object

Returns the value of attribute boundaries.



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# File 'lib/mm/space.rb', line 7

def boundaries
  @boundaries
end

#cost_function(start_morph, to) ⇒ Object

Default cost_function to use if no other one is specified. Takes the root of the sum of the squares, or the generalized Euclidean distance.

start_morph - morph to begin the morph from. This should be a valid morph in

the space (i.e., not out of bounds), and should also work with MM::Metric.

to - Destination vector. There should be one dimension in the Array for each

element in @metric

Returns a Proc that calculates how much the current difference vector differs from the requested difference vector.



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# File 'lib/mm/space.rb', line 86

def cost_function start_morph, to
  @cost_function ||
  ->(current_point) {
    @metric.zip(to).inject(0) {|memo, x|
      distance = x[0].call(start_morph, current_point)
      unless @boundaries.nil?
        start_to_lowest = x[0].call(start_morph, @boundaries[0][0])
        current_to_lowest = x[0].call(current_point, @boundaries[0][0])
        if start_to_lowest > current_to_lowest
          distance = distance * -1.0
        end
      end
      memo = memo + (distance - x[1]).abs ** 2
    } ** 0.5
  }
end

#delta ⇒ Object

Returns the value of attribute delta.



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# File 'lib/mm/space.rb', line 6

def delta
  @delta
end

#max_distance ⇒ Object

Returns the value of attribute max_distance.



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# File 'lib/mm/space.rb', line 7

def max_distance
  @max_distance
end

#metric ⇒ Object

Returns the value of attribute metric.



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# File 'lib/mm/space.rb', line 7

def metric
  @metric
end

#search_klass ⇒ Object

Returns the value of attribute search_klass.



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# File 'lib/mm/space.rb', line 6

def search_klass
  @search_klass
end

Instance Method Details

#enter(locals = {}, &block) ⇒ Object

Allows for morphing within a given block.

locals - Hash of key-value pairs where the key is the name of the local

variable to be created and the value is the value of that variable. Note
that it actually creates *methods*, rather than *variables*, and that these
methods refer to instance variables that are then removed. It could get
buggy if you were to try to create a variable that was the same name as an
existing method or class variable. (default: {})

block - Block to evaluate within the context of the instance.

Returns the last element returned by the block.



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# File 'lib/mm/space.rb', line 132

def enter locals = {}, &block
  create_local_variables locals
  output = instance_eval &block
  remove_local_variables locals
  output
end

#morph(start_morph, to: nil, current_point: nil) ⇒ Object

Morphs to a given point within the space

start_morph - Enumerable object of things to morph from to - Array to morph to, with one element for each dimension

Returns Array of resulting MM::Ratio objects



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# File 'lib/mm/space.rb', line 40

def morph start_morph, to: nil, current_point: nil
  if current_point
    # puts "Finding from #{current_point.map {|r| r.join ' '}}"
    searcher(start_morph, to).find_from_point current_point
  else
    searcher(start_morph, to).find
  end
end