1 files changed, 34 insertions, 0 deletions
diff --git a/contrib/lua-torch/nn/ZipTable.lua b/contrib/lua-torch/nn/ZipTable.lua
new file mode 100644
index 000000000..7b18619eb
--- /dev/null
+++ b/contrib/lua-torch/nn/ZipTable.lua
@@ -0,0 +1,34 @@
+local ZipTable, parent = torch.class('nn.ZipTable', 'nn.Module')
+
+-- input : { {a1,a2}, {b1,b2}, {c1,c2} }
+-- output : { {a1,b1,c1}, {a2,b2,c2} }
+function ZipTable:__init()
+   parent.__init(self)
+   self.output = {}
+   self.gradInput = {}
+end
+
+function ZipTable:updateOutput(inputTable)
+   self.output = {}
+   for i,inTable in ipairs(inputTable) do
+      for j,input in ipairs(inTable) do
+         local output = self.output[j] or {}
+         output[i] = input
+         self.output[j] = output
+      end
+   end
+   return self.output
+end
+
+function ZipTable:updateGradInput(inputTable, gradOutputTable)
+   self.gradInput = {}
+   for i,gradOutTable in ipairs(gradOutputTable) do
+      for j,gradOutput in ipairs(gradOutTable) do
+         local gradInput = self.gradInput[j] or {}
+         gradInput[i] = gradOutput
+         self.gradInput[j] = gradInput
+      end
+   end
+   return self.gradInput
+end
+