Data commit

Task/Continued-fraction/CoffeeScript/continued-fraction.coffee

@@ -0,0 +1,35 @@
+# Compute a continuous fraction of the form
+# a0 + b1 / (a1 + b2 / (a2 + b3 / ...
+continuous_fraction = (f) ->
+  a = f.a
+  b = f.b
+  c = 1
+  for n in [100000..1]
+    c = b(n) / (a(n) + c)
+  a(0) + c
+
+# A little helper.
+p = (a, b) ->
+  console.log a
+  console.log b
+  console.log "---"
+
+do ->
+  fsqrt2 =
+    a: (n) -> if n is 0 then 1 else 2
+    b: (n) -> 1
+  p Math.sqrt(2), continuous_fraction(fsqrt2)
+
+  fnapier =
+    a: (n) -> if n is 0 then 2 else n
+    b: (n) -> if n is 1 then 1 else n - 1
+  p Math.E, continuous_fraction(fnapier)
+
+  fpi =
+    a: (n) ->
+      return 3 if n is 0
+      6
+    b: (n) ->
+      x = 2*n - 1
+      x * x
+  p Math.PI, continuous_fraction(fpi)