2 files changed, 13 insertions, 0 deletions
diff --git a/lib/zipf/SparseVector.rb b/lib/zipf/SparseVector.rb
index 837403a..5d219b8 100644
--- a/lib/zipf/SparseVector.rb
+++ b/lib/zipf/SparseVector.rb
@@ -179,6 +179,15 @@ class SparseVector < Hash
     return new
   end
 
+  def / scalar
+    raise ArgumentError, "Arg is not numeric #{scalar}" unless scalar.is_a? Numeric
+    new = SparseVector.new
+    self.keys.each { |k|
+      new[k] = self[k] / scalar
+    }
+    return new
+  end
+
   def self.mean a
     mean = SparseVector.new
     a.each { |i|
diff --git a/lib/zipf/fileutil.rb b/lib/zipf/fileutil.rb
index ac701da..7ae0c55 100644
--- a/lib/zipf/fileutil.rb
+++ b/lib/zipf/fileutil.rb
@@ -18,6 +18,10 @@ class ReadFile
     @f.gets { |line| yield line }
   end
 
+  def rewind
+    @f.rewind
+  end
+
   def readlines
     @f.readlines
   end