diff --git a/concat.lua b/concat.lua
index 56688d1..5e69ad8 100644
--- a/concat.lua
+++ b/concat.lua
@@ -8,7 +8,6 @@ function torch.concat(result, tensors, dim, index)
       tensors = result
       result = tensors[index].new()
    end
-   result = tensors[index].new()
    
    assert(type(tensors) == 'table', "expecting table at arg 2")
    
@@ -44,3 +43,5 @@ function torch.concat(result, tensors, dim, index)
    end
    return result
 end
+
+torchx.Tensor.concat = torch.concat
diff --git a/find.lua b/find.lua
index 30345b7..a8ee55f 100644
--- a/find.lua
+++ b/find.lua
@@ -1,6 +1,15 @@
 
-function torch.find(tensor, val)
-   assert(tensor:dim() == 1)
+
+function torch.find(res, tensor, val, asTable)
+   if not torch.isTensor(tensor) then
+      asTable = val
+      val = tensor
+      tensor = res
+      if not asTable then
+         res = torch.LongTensor()
+      end
+   end
+   assert(tensor:dim() == 1, "torch.find only supports 1D tensors (for now)")
    local i = 1
    local indice = {}
    tensor:apply(function(x)
@@ -9,5 +18,16 @@ function torch.find(tensor, val)
          end
          i = i + 1
       end)
-   return torch.LongTensor(indice)
+   if asTable then
+      return indice
+   end
+   res:resize(#indice)
+   i = 0
+   res:apply(function()
+         i = i + 1
+         return indice[i]
+      end)
+   return res
 end
+
+torchx.Tensor.find = torch.find
diff --git a/init.lua b/init.lua
index 01342b4..daac808 100644
--- a/init.lua
+++ b/init.lua
@@ -3,8 +3,10 @@ require 'paths'
 require 'sys'
 ffi = require 'ffi'
 
-torchx = {}
+torchx = {Tensor={}}
 
+
+torch.include('torchx', 'extend.lua')
 torch.include('torchx', 'md5.lua')
 torch.include('torchx', 'treemax.lua')
 torch.include('torchx', 'find.lua')
@@ -15,4 +17,14 @@ torch.include('torchx', 'indexdir.lua')
 
 torch.include('torchx', 'test.lua')
 
+local types = {'Byte', 'Char', 'Short', 'Int', 'Long', 'Float', 'Double'}
+local Tensor = torchx.Tensor
+torchx.Tensor = nil
+
+torchx.extend(types, Tensor, true)
+
+function torchx:cuda()
+   torchx:extend({'Cuda'}, Tensor, true)
+end
 
+return torchx
diff --git a/test/test.lua b/test/test.lua
index 4d396c7..daebd9f 100644
--- a/test/test.lua
+++ b/test/test.lua
@@ -26,6 +26,14 @@ function torchxtest.find()
    local tensor = torch.Tensor{1,2,3,4,5,6,0.6,0,2}
    local indice = torch.find(tensor, 2)
    mytester:assertTensorEq(indice, torch.LongTensor{2,9}, 0.00001, "find err")
+   
+   indice = indice.new()
+   indice:find(tensor, 2)
+   mytester:assertTensorEq(indice, torch.LongTensor{2,9}, 0.00001, "find err")
+   
+   local indiceTbl = torch.find(tensor, 2, true)
+   mytester:assert(torch.type(indiceTbl) == 'table', "find asTable type error")
+   mytester:assertTensorEq(indice, torch.LongTensor(indiceTbl), 0.00001, "find asTable value err")
 end
 
 function torchxtest.remap()
@@ -86,6 +94,9 @@ function torchxtest.concat()
    res2:narrow(3,5,6):copy(tensors[2])
    res2:narrow(3,11,8):copy(tensors[3])
    mytester:assertTensorEq(res,res2,0.00001)
+   
+   res:zero():concat(tensors, 3)
+   mytester:assertTensorEq(res,res2,0.00001)
 end
 
 function torchx.test(tests)