1 files changed, 26 insertions, 0 deletions
diff --git a/contrib/lua-torch/nn/CSubTable.lua b/contrib/lua-torch/nn/CSubTable.lua
new file mode 100644
index 000000000..eb7492055
--- /dev/null
+++ b/contrib/lua-torch/nn/CSubTable.lua
@@ -0,0 +1,26 @@
+
+local CSubTable, parent = torch.class('nn.CSubTable', 'nn.Module')
+
+function CSubTable:__init()
+   parent.__init(self)
+   self.gradInput = {}
+end
+
+function CSubTable:updateOutput(input)
+   self.output:resizeAs(input[1]):copy(input[1])
+   self.output:add(-1,input[2])
+   return self.output
+end
+
+function CSubTable:updateGradInput(input, gradOutput)
+   self.gradInput[1] = self.gradInput[1] or input[1].new()
+   self.gradInput[2] = self.gradInput[2] or input[1].new()
+   self.gradInput[1]:resizeAs(input[1]):copy(gradOutput)
+   self.gradInput[2]:resizeAs(input[2]):copy(gradOutput):mul(-1)
+
+   for i=#input+1, #self.gradInput do
+       self.gradInput[i] = nil
+   end
+
+   return self.gradInput
+end