From 631d989d00ace0692a96011e21d4d16481a22735 Mon Sep 17 00:00:00 2001
From: Jeffrey Wilcke <jeffrey@ethereum.org>
Date: Wed, 18 Nov 2015 19:02:32 +0100
Subject: [PATCH] library/math: Added standard math functions

Added standard math library, including:

* Two dimensional euclidean distance
* Square root
* Linear interpolation
---
 library/math.sol | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 library/math.sol

diff --git a/library/math.sol b/library/math.sol
new file mode 100644
index 0000000..84efea5
--- /dev/null
+++ b/library/math.sol
@@ -0,0 +1,28 @@
+/// Standard math library.
+contract Math {
+    /// @dev Returns the square root of x.
+    function sqrt(uint x) returns (uint) {
+        uint y = x;
+        while( true ) {
+            uint z = (y + (x/y))/2;
+            uint w = (z + (x/z))/2;
+            if( w == y) {
+                if( w < y ) return w;
+                else return y;
+            }
+            y = w;
+        }
+    }
+
+    /// @dev Returns the, two dimensional, eucledian distance between two points.
+    function 2dEucDist(uint x_a, uint y_a,  uint x_b, uint y_b) returns (uint) {
+        return sqrt((x_a - y_b) ** 2 + (y_a, - x_b) ** 2);
+    }
+
+    /// @dev Returns the linear interpolation between a and b
+    function lerp(uint x_a, uint y_a, uint x_b, uint y_b, uint delta) returns (uint x, uint y) {
+        x = x_a * delta + x_b * delta;
+        y = y_a * delta + y_b *delta;
+        return x, y;
+    }
+}