Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/interpolate/add/core/array.rb

Overview

Extension(s) for the Ruby Array class.

Author

Adam Collins

License

Licensed under the MIT license.

Instance Method Summary collapse

Instance Method Details

#interpolate(other, balance) ⇒ Object

Returns a new Array in which each element is the interpolated value between self and other. balance should be a Float from 0.0 to 1.0 where the value is a ratio between self and other. self and other should be arrays of equal, non-zero length.

Between two interpolation points, let’s say a and b, the final result will be c where c[0] is the interpolation of a[0] and b[0] and c[1] is interpolated between a[1] and b[1] and so on, up to c[c.length - 1].

This method is intentionally abstract to allow for the interpolation of nested arrays. In this case, both arrays need to have the same array structure (same number of dimensions, equal length in each dimension), but the contents can, of course, be different.

A balance less than or equal to 0.0 returns self, while a balance greater than or equal to 1.0 returns other.



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# File 'lib/interpolate/add/core/array.rb', line 32

def interpolate(other, balance)
  if (self.length < 1) then
    raise ArgumentError, "cannot interpolate empty array"
  end

  if self.length != other.length then
    raise ArgumentError, "cannot interpolate between arrays of different length"
  end

  # catch the easy cases
  return self.dup if (balance <= 0.0)
  return other.dup if (balance >= 1.0)

  final = Array.new

  self.each_with_index do |value, index|
    unless value.respond_to? :interpolate then
      raise "array element does not respond to :interpolate"
    end

    final[index] = value.interpolate(other[index], balance)
  end

  final
end