1 files changed, 43 insertions, 0 deletions
diff --git a/lib/nlp_ruby/Vector.rb b/lib/nlp_ruby/Vector.rb
new file mode 100644
index 0000000..c749ed9
--- /dev/null
+++ b/lib/nlp_ruby/Vector.rb
@@ -0,0 +1,43 @@
+class Vector < Array
+
+  def sum
+    self.inject(:+)
+  end
+
+  def average
+    self.sum/self.size.to_f
+  end
+
+  def variance
+    avg = self.average
+    var = 0.0
+    self.each { |i| var += (avg - i)**2 }
+    var
+  end
+
+  def stddev list_of_values, decimal_places=-1
+    Math.sqrt self.variance
+  end
+
+  def dot other
+    return nil if self.size!=other.size
+    sum = 0.0
+    self.each_with_index { |i,j| sum += i*other[j] }
+    return sum
+  end
+
+  def magnitude
+     Math.sqrt self.inject { |sum,i| sum+i**2 }
+  end
+
+  def cosinus_sim other
+    return self.dot(other)/(self.mag*other.mag)
+  end
+
+  def euclidian_dist other
+    sum = 0.0
+    self.each_with_index { |i,j| sum += (i - other[j])**2 }
+    return Math.sqrt(sum)
+  end
+end
+