1 files changed, 46 insertions, 0 deletions
diff --git a/contrib/lua-torch/nn/CMinTable.lua b/contrib/lua-torch/nn/CMinTable.lua
new file mode 100644
index 000000000..25b9a19a2
--- /dev/null
+++ b/contrib/lua-torch/nn/CMinTable.lua
@@ -0,0 +1,46 @@
+local CMinTable, parent = torch.class('nn.CMinTable', 'nn.Module')
+
+function CMinTable:__init()
+   parent.__init(self)
+   self.gradInput = {}
+   self.minIdx = torch.Tensor()
+   self.mask = torch.Tensor()
+   self.minVals = torch.Tensor()
+   self.gradMaxVals = torch.Tensor()
+end
+
+function CMinTable:updateOutput(input)
+   self.output:resizeAs(input[1]):copy(input[1])
+   self.minIdx:resizeAs(input[1]):fill(1)
+   for i=2,#input do
+      self.maskByteTensor = self.maskByteTensor or
+         (torch.type(self.output) == 'torch.CudaTensor' and
+         torch.CudaByteTensor() or torch.ByteTensor())
+      self.mask:lt(input[i], self.output)
+      self.maskByteTensor:resize(self.mask:size()):copy(self.mask)
+      self.minIdx:maskedFill(self.maskByteTensor, i)
+      self.minVals:maskedSelect(input[i], self.maskByteTensor)
+      self.output:maskedCopy(self.maskByteTensor, self.minVals)
+   end
+   return self.output
+end
+
+function CMinTable:updateGradInput(input, gradOutput)
+   for i=1,#input do
+      self.gradInput[i] = self.gradInput[i] or input[i].new()
+      self.gradInput[i]:resizeAs(input[i]):fill(0.0)
+      self.maskByteTensor = self.maskByteTensor or
+         (torch.type(self.output) == 'torch.CudaTensor' and
+         torch.CudaByteTensor() or torch.ByteTensor())
+      self.mask:eq(self.minIdx, i)
+      self.maskByteTensor:resize(self.mask:size()):copy(self.mask)
+      self.gradMaxVals:maskedSelect(gradOutput, self.maskByteTensor)
+      self.gradInput[i]:maskedCopy(self.maskByteTensor, self.gradMaxVals)
+   end
+
+   for i=#input+1, #self.gradInput do
+       self.gradInput[i] = nil
+   end
+
+   return self.gradInput
+end