Data commit

Task/Vector/Ruby/vector.rb

@@ -0,0 +1,54 @@
+class Vector
+  def self.polar(r, angle=0)
+    new(r*Math.cos(angle), r*Math.sin(angle))
+  end
+
+  attr_reader :x, :y
+
+  def initialize(x, y)
+    raise TypeError unless x.is_a?(Numeric) and y.is_a?(Numeric)
+    @x, @y = x, y
+  end
+
+  def +(other)
+    raise TypeError if self.class != other.class
+    self.class.new(@x + other.x, @y + other.y)
+  end
+
+  def -@;       self.class.new(-@x, -@y)        end
+  def -(other)  self + (-other)                 end
+
+  def *(scalar)
+    raise TypeError unless scalar.is_a?(Numeric)
+    self.class.new(@x * scalar, @y * scalar)
+  end
+
+  def /(scalar)
+    raise TypeError unless scalar.is_a?(Numeric) and scalar.nonzero?
+    self.class.new(@x / scalar, @y / scalar)
+  end
+
+  def r;        @r     ||= Math.hypot(@x, @y)   end
+  def angle;    @angle ||= Math.atan2(@y, @x)   end
+  def polar;    [r, angle]                      end
+  def rect;     [@x, @y]                        end
+  def to_s;     "#{self.class}#{[@x, @y]}"      end
+  alias inspect to_s
+end
+
+p v = Vector.new(1,1)                   #=> Vector[1, 1]
+p w = Vector.new(3,4)                   #=> Vector[3, 4]
+p v + w                                 #=> Vector[4, 5]
+p v - w                                 #=> Vector[-2, -3]
+p -v                                    #=> Vector[-1, -1]
+p w * 5                                 #=> Vector[15, 20]
+p w / 2.0                               #=> Vector[1.5, 2.0]
+p w.x                                   #=> 3
+p w.y                                   #=> 4
+p v.polar                               #=> [1.4142135623730951, 0.7853981633974483]
+p w.polar                               #=> [5.0, 0.9272952180016122]
+p z = Vector.polar(1, Math::PI/2)       #=> Vector[6.123031769111886e-17, 1.0]
+p z.rect                                #=> [6.123031769111886e-17, 1.0]
+p z.polar                               #=> [1.0, 1.5707963267948966]
+p z = Vector.polar(-2, Math::PI/4)      #=> Vector[-1.4142135623730951, -1.414213562373095]
+p z.polar                               #=> [2.0, -2.356194490192345]