diff --git a/index.js b/index.js
index 3a343d655..d20e2d897 100644
--- a/index.js
+++ b/index.js
@@ -142,7 +142,7 @@ function create (config) {
   math.import(require('./lib/function/matrix/size'));
   math.import(require('./lib/function/matrix/squeeze'));
   require('./lib/function/matrix/subset')(math, _config);
-  require('./lib/function/matrix/trace')(math, _config);
+  math.import(require('./lib/function/matrix/trace'));
   math.import(require('./lib/function/matrix/transpose'));
   require('./lib/function/matrix/zeros')(math, _config);
 
diff --git a/lib/function/matrix/trace.js b/lib/function/matrix/trace.js
index 377e0feb6..82ed19b52 100644
--- a/lib/function/matrix/trace.js
+++ b/lib/function/matrix/trace.js
@@ -1,13 +1,12 @@
 'use strict';
 
-module.exports = function (math) {
-  var util = require('../../util/index'),
+var clone = require('../../util/object').clone;
+var format = require('../../util/string').format;
 
-      Matrix = math.type.Matrix,
-
-      object = util.object,
-      array = util.array,
-      string = util.string;
+function factory (type, config, load, typed) {
+  
+  var matrix = load(require('../construction/matrix'));
+  var add = load(require('../arithmetic/add'));
 
   /**
    * Calculate the trace of a matrix: the sum of the elements on the main
@@ -36,61 +35,160 @@ module.exports = function (math) {
    *
    * @return {Number} The trace of `x`
    */
-  math.trace = function trace (x) {
-    if (arguments.length != 1) {
-      throw new math.error.ArgumentsError('trace', arguments.length, 1);
-    }
-
-    // check x is a matrix
-    if (x instanceof Matrix) {
-      // use optimized operation for the matrix storage format
-      return x.trace();
-    }
+  var trace = typed('trace', {
     
-    // size
-    var size;
-    if (x instanceof Array) {
-      // calculate sixe
-      size = array.size(x);
-    }
-    else {
-      // a scalar
-      size = [];
-    }
+    'Array': function (x) {
+      // use dense matrix implementation
+      return trace(matrix(x));
+    },
 
+    'Matrix': function (x) {
+      // result
+      var c;
+      // process storage format
+      switch (x.storage()) {
+        case 'dense':
+          c = _denseTrace(x);
+          break;
+        case 'ccs':
+          c = _ccsTrace(x);
+          break;
+        case 'crs':
+          c = _crsTrace(x);
+          break;
+      }
+      return c;
+    },
+    
+    'any': function (x) {
+      return clone(x);
+    }
+  });
+  
+  var _denseTrace = function (m) {
+    // matrix size & data
+    var size = m._size;
+    var data = m._data;
+    
+    // process dimensions
     switch (size.length) {
-      case 0:
-        // scalar
-        return object.clone(x);
-
       case 1:
         // vector
         if (size[0] == 1) {
-          // clone value
-          return object.clone(x[0]);
+          // return data[0]
+          return clone(data[0]);
         }
-        throw new RangeError('Array must be square (size: ' + string.format(size) + ')');
-
+        throw new RangeError('Matrix must be square (size: ' + format(size) + ')');
       case 2:
-        // two dimensional array
+        // two dimensional
         var rows = size[0];
         var cols = size[1];
-        // check array is square
-        if (rows == cols) {
-          // diagonal sum
+        if (rows === cols) {
+          // calulate sum
           var sum = 0;
           // loop diagonal
-          for (var i = 0; i < x.length; i++) {
-            // sum
-            sum = math.add(sum, x[i][i]);
-          }
+          for (var i = 0; i < rows; i++)
+            sum = add(sum, data[i][i]);
+          // return trace
           return sum;
         }
-        throw new RangeError('Array must be square (size: ' + string.format(size) + ')');
-
+        throw new RangeError('Matrix must be square (size: ' + format(size) + ')');        
       default:
-        // multi dimensional array
-        throw new RangeError('Matrix must be two dimensional (size: ' + string.format(size) + ')');
+        // multi dimensional
+        throw new RangeError('Matrix must be two dimensional (size: ' + format(size) + ')');
     }
   };
-};
+  
+  var _ccsTrace = function (m) {
+    // matrix arrays
+    var values = m._values;
+    var index = m._index;
+    var ptr = m._ptr;
+    var size = m._size;
+    // check dimensions
+    var rows = size[0];
+    var columns = size[1];
+    // matrix must be square
+    if (rows === columns) {
+      // calulate sum
+      var sum = 0;
+      // check we have data (avoid looping columns)
+      if (values.length > 0) {
+        // loop columns
+        for (var j = 0; j < columns; j++) {
+          // k0 <= k < k1 where k0 = _ptr[j] && k1 = _ptr[j+1]
+          var k0 = ptr[j];
+          var k1 = ptr[j + 1];
+          // loop k within [k0, k1[
+          for (var k = k0; k < k1; k++) {
+            // row index
+            var i = index[k];
+            // check row
+            if (i === j) {
+              // accumulate value
+              sum = add(sum, values[k]);
+              // exit loop
+              break;
+            }
+            if (i > j) {
+              // exit loop, no value on the diagonal for column j
+              break;
+            }
+          }
+        }
+      }
+      // return trace
+      return sum;
+    }
+    throw new RangeError('Matrix must be square (size: ' + format(size) + ')');   
+  };
+  
+  var _crsTrace = function (m) {
+    // matrix arrays
+    var values = m._values;
+    var index = m._index;
+    var ptr = m._ptr;
+    var size = m._size;
+    // check dimensions
+    var rows = size[0];
+    var columns = size[1];
+    // matrix must be square
+    if (rows === columns) {
+      // calulate sum
+      var sum = 0;
+      // check we have data (avoid looping rows)
+      if (values.length > 0) {
+        // loop rows
+        for (var i = 0; i < rows; i++) {
+          // k0 <= k < k1 where k0 = _ptr[i] && k1 = _ptr[i+1]
+          var k0 = ptr[i];
+          var k1 = ptr[i + 1];
+          // loop k within [k0, k1[
+          for (var k = k0; k < k1; k++) {
+            // column index
+            var j = index[k];
+            // check row
+            if (i === j) {
+              // accumulate value
+              sum = add(sum, values[k]);
+              // exit loop
+              break;
+            }
+            if (j > i) {
+              // exit loop, no value on the diagonal for column j
+              break;
+            }
+          }
+        }
+      }
+      // return trace
+      return sum;
+    }
+    throw new RangeError('Matrix must be square (size: ' + format(size) + ')');     
+  };
+  
+  return trace;
+}
+
+exports.name = 'trace';
+exports.factory = factory;
diff --git a/lib/type/matrix/CcsMatrix.js b/lib/type/matrix/CcsMatrix.js
index 6fad5ddd3..d9371ad56 100644
--- a/lib/type/matrix/CcsMatrix.js
+++ b/lib/type/matrix/CcsMatrix.js
@@ -14,9 +14,8 @@ var isInteger = util.number.isInteger;
 
 var validateIndex = array.validateIndex;
 
-function factory (type, config, load, typed) {
+function factory (type, config, load) {
   
-  var add = load(require('../../function/arithmetic/add'));
   var multiply = load(require('../../function/arithmetic/multiply'));
   var equal = load(require('../../function/relational/equal'));
   
@@ -1092,57 +1091,6 @@ function factory (type, config, load, typed) {
     });
   };
   
-  /**
-   * Calculate the trace of a matrix: the sum of the elements on the main
-   * diagonal of a square matrix.
-   *
-   * See also:
-   *
-   *    diagonal
-   *
-   * @returns {Number}       The matrix trace
-   */
-  CcsMatrix.prototype.trace = function () {
-    // size
-    var size = this._size;
-    // check dimensions
-    var rows = size[0];
-    var columns = size[1];
-    // matrix must be square
-    if (rows === columns) {
-      // calulate sum
-      var sum = 0;
-      // check we have data (avoid looping columns)
-      if (this._values.length > 0) {
-        // loop columns
-        for (var j = 0; j < columns; j++) {
-          // k0 <= k < k1 where k0 = _ptr[j] && k1 = _ptr[j+1]
-          var k0 = this._ptr[j];
-          var k1 = this._ptr[j + 1];
-          // loop k within [k0, k1[
-          for (var k = k0; k < k1; k++) {
-            // row index
-            var i = this._index[k];
-            // check row
-            if (i === j) {
-              // accumulate value
-              sum = add(sum, this._values[k]);
-              // exit loop
-              break;
-            }
-            if (i > j) {
-              // exit loop, no value on the diagonal for column j
-              break;
-            }
-          }
-        }
-      }
-      // return trace
-      return sum;
-    }
-    throw new RangeError('Matrix must be square (size: ' + string.format(size) + ')');        
-  };
-  
   /**
    * Multiply the matrix values times the argument.
    *
diff --git a/lib/type/matrix/CrsMatrix.js b/lib/type/matrix/CrsMatrix.js
index cb5104d50..254d0b274 100644
--- a/lib/type/matrix/CrsMatrix.js
+++ b/lib/type/matrix/CrsMatrix.js
@@ -14,7 +14,7 @@ var isInteger = util.number.isInteger;
 
 var validateIndex = array.validateIndex;
 
-function factory (type, config, load, typed) {
+function factory (type, config, load) {
 
   var add = load(require('../../function/arithmetic/add'));
   var multiply = load(require('../../function/arithmetic/multiply'));
@@ -1085,57 +1085,6 @@ function factory (type, config, load, typed) {
       size: [rows, columns]
     });
   };
-
-  /**
-   * Calculate the trace of a matrix: the sum of the elements on the main
-   * diagonal of a square matrix.
-   *
-   * See also:
-   *
-   *    diagonal
-   *
-   * @returns {Number}       The matrix trace
-   */
-  CrsMatrix.prototype.trace = function () {
-    // size
-    var size = this._size;
-    // check dimensions
-    var rows = size[0];
-    var columns = size[1];
-    // matrix must be square
-    if (rows === columns) {
-      // calulate sum
-      var sum = 0;
-      // check we have data (avoid looping rows)
-      if (this._values.length > 0) {
-        // loop rows
-        for (var i = 0; i < rows; i++) {
-          // k0 <= k < k1 where k0 = _ptr[i] && k1 = _ptr[i+1]
-          var k0 = this._ptr[i];
-          var k1 = this._ptr[i + 1];
-          // loop k within [k0, k1[
-          for (var k = k0; k < k1; k++) {
-            // column index
-            var j = this._index[k];
-            // check row
-            if (i === j) {
-              // accumulate value
-              sum = add(sum, this._values[k]);
-              // exit loop
-              break;
-            }
-            if (j > i) {
-              // exit loop, no value on the diagonal for column j
-              break;
-            }
-          }
-        }
-      }
-      // return trace
-      return sum;
-    }
-    throw new RangeError('Matrix must be square (size: ' + string.format(size) + ')');        
-  };
   
   /**
    * Multiply the matrix values times the argument.
diff --git a/lib/type/matrix/DenseMatrix.js b/lib/type/matrix/DenseMatrix.js
index de5838453..069dc1a48 100644
--- a/lib/type/matrix/DenseMatrix.js
+++ b/lib/type/matrix/DenseMatrix.js
@@ -13,13 +13,10 @@ var isInteger = util.number.isInteger;
 
 var validateIndex = array.validateIndex;
 
-function factory (type, config, load, typed) {
+function factory (type, config, load) {
   
   var add = load(require('../../function/arithmetic/add'));
-  var divideScalar = load(require('../../function/arithmetic/divideScalar'));
   var multiply = load(require('../../function/arithmetic/multiply'));
-  var subtract = load(require('../../function/arithmetic/subtract'));
-  var equal = load(require('../../function/relational/equal'));
   
   var Index = type.Index;
   var BigNumber = type.BigNumber;
@@ -748,49 +745,6 @@ function factory (type, config, load, typed) {
       size: [rows, columns]
     });
   };
-  
-  /**
-   * Calculate the trace of a matrix: the sum of the elements on the main
-   * diagonal of a square matrix.
-   *
-   * See also:
-   *
-   *    diagonal
-   *
-   * @returns {Number}       The matrix trace
-   */
-  DenseMatrix.prototype.trace = function () {
-    // size & data
-    var size = this._size;
-    var data = this._data;
-    // check dimensions
-    switch (size.length) {
-      case 1:
-        // vector
-        if (size[0] == 1) {
-          // return data[0]
-          return object.clone(data[0]);
-        }
-        throw new RangeError('Matrix must be square (size: ' + string.format(size) + ')');
-      case 2:
-        // two dimensional array
-        var rows = size[0];
-        var cols = size[1];
-        if (rows === cols) {
-          // calulate sum
-          var sum = 0;
-          // loop diagonal
-          for (var i = 0; i < rows; i++)
-            sum = add(sum, data[i][i]);
-          // return trace
-          return sum;
-        }
-        throw new RangeError('Matrix must be square (size: ' + string.format(size) + ')');        
-      default:
-        // multi dimensional array
-        throw new RangeError('Matrix must be two dimensional (size: ' + string.format(size) + ')');
-    }
-  };
 
   /**
    * Generate a matrix from a JSON object
diff --git a/test/function/matrix/trace.test.js b/test/function/matrix/trace.test.js
index 83bd82315..395a24d37 100644
--- a/test/function/matrix/trace.test.js
+++ b/test/function/matrix/trace.test.js
@@ -210,4 +210,108 @@ describe('trace', function() {
     assert.equal(expression.toTex(), '\\mathrm{tr}\\left({\\begin{bmatrix}1&2\\\\3&4\\\\\\end{bmatrix}}\\right)');
   });
 
+  describe('DenseMatrix', function () {
+
+    it('should calculate trace on a square matrix', function() {
+      var m = math.matrix([
+        [1, 2],
+        [4, -2]
+      ]);
+      assert.equal(math.trace(m), -1);
+
+      m = math.matrix([
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0]
+      ]);
+      assert.equal(math.trace(m), 0);
+
+      m = math.matrix([
+        [1, 0, 0, 0],
+        [0, 0, 2, 0],
+        [1, 0, 0, 0],
+        [0, 0, 1, 9]
+      ]);
+      assert.equal(math.trace(m), 10);
+    });
+
+    it('should throw an error for invalid matrix', function() {
+      var m = math.matrix([
+        [1, 2, 3],
+        [4, 5, 6]
+      ]);
+      assert.throws(function () { math.trace(m); });
+    });
+  });
+  
+  describe('CcsMatrix', function () {
+
+    it('should calculate trace on a square matrix', function() {
+      var m = math.matrix([
+        [1, 2],
+        [4, -2]
+      ], 'ccs');
+      assert.equal(math.trace(m), -1);
+
+      m = math.matrix([
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0]
+      ], 'ccs');
+      assert.equal(math.trace(m), 0);
+
+      m = math.matrix([
+        [1, 0, 0, 0],
+        [0, 0, 2, 0],
+        [1, 0, 0, 0],
+        [0, 0, 1, 9]
+      ], 'ccs');
+      assert.equal(math.trace(m), 10);
+    });
+
+    it('should throw an error for invalid matrix', function() {
+      var m = math.matrix([
+        [1, 2, 3],
+        [4, 5, 6]
+      ], 'ccs');
+      assert.throws(function () { math.trace(m); });
+    });
+  });
+  
+  describe('CrsMatrix', function () {
+
+    it('should calculate trace on a square matrix', function() {
+      var m = math.matrix([
+        [1, 2],
+        [4, -2]
+      ], 'crs');
+      assert.equal(math.trace(m), -1);
+
+      m = math.matrix([
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0],
+        [0, 0, 0, 0]
+      ], 'crs');
+      assert.equal(math.trace(m), 0);
+
+      m = math.matrix([
+        [1, 0, 0, 0],
+        [0, 0, 2, 0],
+        [1, 0, 0, 0],
+        [0, 0, 1, 9]
+      ], 'crs');
+      assert.equal(math.trace(m), 10);
+    });
+
+    it('should throw an error for invalid matrix', function() {
+      var m = math.matrix([
+        [1, 2, 3],
+        [4, 5, 6]
+      ], 'crs');
+      assert.throws(function () { math.trace(m); });
+    });
+  });
 });
diff --git a/test/type/matrix/CcsMatrix.test.js b/test/type/matrix/CcsMatrix.test.js
index c92c3e363..d5ac3c50d 100644
--- a/test/type/matrix/CcsMatrix.test.js
+++ b/test/type/matrix/CcsMatrix.test.js
@@ -1758,41 +1758,6 @@ describe('CcsMatrix', function() {
     });
   });
   
-  describe('trace', function () {
-
-    it('should calculate trace on a square matrix', function() {
-      var m = new CcsMatrix([
-        [1, 2],
-        [4, -2]
-      ]);
-      assert.equal(m.trace(), -1);
-      
-      m = new CcsMatrix([
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0]
-      ]);
-      assert.equal(m.trace(), 0);
-      
-      m = new CcsMatrix([
-        [1, 0, 0, 0],
-        [0, 0, 2, 0],
-        [1, 0, 0, 0],
-        [0, 0, 1, 9]
-      ]);
-      assert.equal(m.trace(), 10);
-    });
-    
-    it('should throw an error for invalid matrix', function() {
-      var m = new CcsMatrix([
-        [1, 2, 3],
-        [4, 5, 6]
-      ]);
-      assert.throws(function () { m.trace(); });
-    });
-  });
-  
   describe('multiply', function () {
     
     it('should multiply matrix x scalar', function() {
diff --git a/test/type/matrix/CrsMatrix.test.js b/test/type/matrix/CrsMatrix.test.js
index 866a5b824..dde8d17e7 100644
--- a/test/type/matrix/CrsMatrix.test.js
+++ b/test/type/matrix/CrsMatrix.test.js
@@ -1740,41 +1740,6 @@ describe('CrsMatrix', function() {
     });
   });
 
-  describe('trace', function () {
-
-    it('should calculate trace on a square matrix', function() {
-      var m = new CrsMatrix([
-        [1, 2],
-        [4, -2]
-      ]);
-      assert.equal(m.trace(), -1);
-
-      m = new CrsMatrix([
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0]
-      ]);
-      assert.equal(m.trace(), 0);
-
-      m = new CrsMatrix([
-        [1, 0, 0, 0],
-        [0, 0, 2, 0],
-        [1, 0, 0, 0],
-        [0, 0, 1, 9]
-      ]);
-      assert.equal(m.trace(), 10);
-    });
-
-    it('should throw an error for invalid matrix', function() {
-      var m = new CrsMatrix([
-        [1, 2, 3],
-        [4, 5, 6]
-      ]);
-      assert.throws(function () { m.trace(); });
-    });
-  });
-  
   describe('multiply', function () {
 
     it('should multiply matrix x scalar', function() {
diff --git a/test/type/matrix/DenseMatrix.test.js b/test/type/matrix/DenseMatrix.test.js
index e10b7b8cd..b9f966b6f 100644
--- a/test/type/matrix/DenseMatrix.test.js
+++ b/test/type/matrix/DenseMatrix.test.js
@@ -1086,41 +1086,6 @@ describe('DenseMatrix', function() {
     });
   });
   
-  describe('trace', function () {
-
-    it('should calculate trace on a square matrix', function() {
-      var m = new DenseMatrix([
-        [1, 2],
-        [4, -2]
-      ]);
-      assert.equal(m.trace(), -1);
-
-      m = new DenseMatrix([
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0],
-        [0, 0, 0, 0]
-      ]);
-      assert.equal(m.trace(), 0);
-
-      m = new DenseMatrix([
-        [1, 0, 0, 0],
-        [0, 0, 2, 0],
-        [1, 0, 0, 0],
-        [0, 0, 1, 9]
-      ]);
-      assert.equal(m.trace(), 10);
-    });
-
-    it('should throw an error for invalid matrix', function() {
-      var m = new DenseMatrix([
-        [1, 2, 3],
-        [4, 5, 6]
-      ]);
-      assert.throws(function () { m.trace(); });
-    });
-  });
-  
   describe('multiply', function () {
 
     it('should multiply matrix x scalar', function() {