nonuniq.rb in facets-2.9.3

- old
+ new

@@ -2,11 +2,11 @@
 
   # Returns a list of non-unique elements
   #
   #   [1,1,2,2,3,4,5].nonuniq  #=> [1,2]
   #
-  # CREDIT: Martin DeMello
+  # @author Martin DeMello
 
   def nonuniq
     h1 = {}
     h2 = {}
     each {|i|
@@ -14,11 +14,11 @@
       h1[i] = true
     }
     h2.keys
   end
 
-  #
+  # Same as `#nonuniq` but acting in place.
   def nonuniq!
     h1 = {}
     h2 = {}
     each {|i|
       h2[i] = true if h1[i]
@@ -27,11 +27,48 @@
     self.replace(h2.keys)
   end
 
   # Return list of duplictate elements.
   #
-  # CREDIT: Thibaut Barrère
+  # @param [Integer] min
+  #   The minimum number of duplicatation necessary for inclusion.
+  #
+  # @author Rebort Dober (current implementation)
+  # @author Thibaut Barrère
 
-  alias_method :duplicates, :nonuniq
+  def duplicates(min=2)
+    h = Hash.new( 0 )
+    each {|i|
+      h[i] += 1
+    }
+    h.delete_if{|_,v| v < min}.keys
+  end
+
+  # Returns a list of elements that occur +n+ times.
+  #
+  #  [0,1,1,1,3,0,1,2,4].occurent(3) #=> [1]
+  #
+  # If +n+ is a Range then returns elements that occur a number
+  # of time within the range.
+  #
+  #  [0,1,1,1,3,0,1,2,4].occurent(2..4) #=> [0,1]
+  #
+  # @author Robert Dober
+
+  def occurent(n=2)
+    h = Hash.new( 0 )
+    each do |i|
+      h[i] += 1
+    end
+
+    case n
+    when nil
+      h.delete_if{ |_,v| ! yield(v) }.keys
+    when Range
+      h.delete_if{ |_,v| ! n.include?(v) }.keys
+    else
+      h.delete_if{|_,v| v != n}.keys
+    end
+  end
 
 end
 