Module: VectorSpace::Arithmetic

Defined in:
lib/vector_space/arithmetic.rb

Overview

These operations depend only upon addition and multiplication of the underlying values, so work in a vector space

Instance Method Summary collapse

Instance Method Details

#*(n) ⇒ Object

Scalar multiplication



14
15
16
 
# File 'lib/vector_space/arithmetic.rb', line 14

def *(n)
  operate_on_values { |value| value * n }
end

#+(vector) ⇒ Object

Vector addition



5
6
7
8
9
10
11
 
# File 'lib/vector_space/arithmetic.rb', line 5

def +(vector)
  if compatible_with?(vector)
    operate_on_values(vector) { |a, b| a + b }
  else
    raise ArgumentError, "can't add #{vector.inspect} to #{self.inspect}"
  end
end

#-(vector) ⇒ Object

Vector subtraction (by addition)



24
25
26
 
# File 'lib/vector_space/arithmetic.rb', line 24

def -(vector)
  self + (-vector)
end

#-@ ⇒ Object

Additive inverse



19
20
21
 
# File 'lib/vector_space/arithmetic.rb', line 19

def -@
  operate_on_values { |value| -value }
end

#/(divisor) ⇒ Object 



28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
 
# File 'lib/vector_space/arithmetic.rb', line 28

def /(divisor)
  if divisor.zero?
    raise ZeroDivisionError
  else
    if divisor.is_a?(Numeric)
      # Scalar division (by multiplication)
      self * (1.0 / divisor)
    elsif compatible_with?(divisor)
      # Vector division
      map_values(dimensions.reject { |dimension| divisor.project(dimension).zero? }, divisor) { |a, b| a / b }.min
    else
      raise ArgumentError, "can't divide #{self.inspect} by #{divisor.inspect}"
    end
  end
end