Floating point numbers equality

lib/function/arithmetic/equal.js

@@ -14,7 +14,22 @@ module.exports = function (math) {
       isComplex = Complex.isComplex,
       isUnit = Unit.isUnit,
       isCollection = collection.isCollection;
+ 
+  var _nearlyEqual = function(x, y) {
+final float absA = Math.abs(a);
+final float absB = Math.abs(b);
+final float diff = Math.abs(a - b);
 
+if (a == b) { // shortcut, handles infinities
+return true;
+} else if (a == 0 || b == 0 || diff < Float.MIN_NORMAL) {
+// a or b is zero or both are extremely close to it
+// relative error is less meaningful here
+return diff < (epsilon * Float.MIN_NORMAL);
+} else { // use relative error
+return diff / (absA + absB) < epsilon;
+}
+}
   /**
    * Check if value x equals y,
    *

test/function/arithmetic/equal.test.js

@@ -16,6 +16,10 @@ describe('equal', function() {
     assert.equal(equal(-2, 2), false);
   });
 
+  it('should compare two floating point numbers correctly', function() {
+    assert.equal(equal(0.3 - 0.2, 0.1), true);
+  });
+
   it('should compare two booleans', function() {
     assert.equal(equal(true, true), true);
     assert.equal(equal(true, false), false);