First commit of partial RosettaCode contents.

Pushing this for testing purposes. Lots of work still needed.

Task/Pi/Ruby/pi-2.rb

@@ -0,0 +1,28 @@
+def pi
+  q, r, t, k, n, l = 1, 0, 1, 1, 3, 3
+  dot = nil
+  loop do
+    if 4*q+r-t < n*t
+      yield n
+      if dot.nil?
+        yield '.'
+        dot = '.'
+      end
+      nr = 10*(r-n*t)
+      n = ((10*(3*q+r)) / t) - 10*n
+      q *= 10
+      r = nr
+    else
+      nr = (2*q+r) * l
+      nn = (q*(7*k+2)+r*l) / (t*l)
+      q *= k
+      t *= l
+      l += 2
+      k += 1
+      n = nn
+      r = nr
+    end
+  end
+end
+
+pi {|digit| print digit; $stdout.flush}

Task/Pi/Ruby/pi.rb

@@ -0,0 +1,20 @@
+# Calculate Pi using the Arithmetic Geometric Mean of 1 and 1/sqrt(2)
+#
+#
+#  Nigel_Galloway
+#  March 8th., 2012.
+#
+require 'flt'
+Flt::BinNum.Context.precision = 8192
+a = n = 1
+g = 1 / Flt::BinNum(2).sqrt
+z = 0.25
+(0..17).each{
+  x = [(a + g) * 0.5, (a * g).sqrt]
+  var = x[0] - a
+  z -= var * var * n
+  n += n
+  a = x[0]
+  g = x[1]
+}
+puts a * a / z