1 files changed, 43 insertions, 0 deletions
diff --git a/contrib/lua-torch/nn/NarrowTable.lua b/contrib/lua-torch/nn/NarrowTable.lua
new file mode 100644
index 000000000..17429f3b1
--- /dev/null
+++ b/contrib/lua-torch/nn/NarrowTable.lua
@@ -0,0 +1,43 @@
+local NarrowTable, parent = torch.class('nn.NarrowTable', 'nn.Module')
+
+function NarrowTable:__init(offset, length)
+   parent.__init(self)
+   self.offset = offset
+   self.length = length or 1
+   if not offset then
+      error('nn.NarrowTable(offset, length)')
+   end
+
+   self.output = {}
+   self.gradInput = {}
+end
+
+function NarrowTable:updateOutput(input)
+   for k,v in ipairs(self.output) do self.output[k] = nil end
+   for i=1,self.length do
+      self.output[i] = input[self.offset+i-1]
+   end
+   return self.output
+end
+
+function NarrowTable:updateGradInput(input, gradOutput)
+   for i=1,#gradOutput do
+      self.gradInput[self.offset+i-1] = gradOutput[i]
+   end
+   for i=1,#input do
+      if (i < self.offset) or (i >= self.offset + self.length) then
+         self.gradInput[i] = nn.utils.recursiveResizeAs(self.gradInput[i], input[i])
+         nn.utils.recursiveFill(self.gradInput[i], 0)
+      end
+   end
+   for i=#input+1,#self.gradInput do self.gradInput[i] = nil end
+   return self.gradInput
+end
+
+function NarrowTable:type(type, tensorCache)
+   self.output = {}
+   self.gradInput = {}
+   return parent.type(self, type, tensorCache)
+end
+
+NarrowTable.clearState = nn.Identity.clearState