Update.

diff --git a/dagnn.lua b/dagnn.lua
index 05672e9..8a02cc6 100755 (executable)
--- a/dagnn.lua
+++ b/dagnn.lua
@@ -152,6 +152,22 @@ function DAG:updateOutput(input)
    return self.output
 end
 
+function DAG:computeGradInput(gradInputSucc)
+   local gi
+   if #gradInputSucc == 1 then
+      gi = gradInputSucc[1] -- we avoid a clone()
+   elseif #gradInputSucc > 1 then
+      for k = 1, #gradInputSucc do
+         if gi then
+            gi:add(gradInputSucc[k])
+         else
+            gi = gradInputSucc[k]:clone()
+         end
+      end
+   end
+   return gi
+end
+
 function DAG:updateGradInput(input, gradOutput)
    self:putInOrder()
 
@@ -160,6 +176,11 @@ function DAG:updateGradInput(input, gradOutput)
       self.outputModules, gradOutput
    )
 
+   self:nestApply(
+      function(nnm, i) self.node[nnm].input = i end,
+      self.inputModules, input
+   )
+
    for _, node in pairs(self.node) do
       node.gradInputSucc = {}
    end
@@ -167,23 +188,10 @@ function DAG:updateGradInput(input, gradOutput)
    for k = #self.sorted, 1, -1 do
       local nnm = self.sorted[k]
       local node = self.node[nnm]
-      local pred, succ, gradInputSucc = node.pred, node.succ, node.gradInputSucc
+      local pred, gradInputSucc = node.pred, node.gradInputSucc
 
       if #gradInputSucc > 0 then
-         -- We update nnm:gradInput
-         local gi
-         if #gradInputSucc == 1 then
-            gi = gradInputSucc[1] -- we avoid a clone()
-         elseif #gradInputSucc > 1 then
-            for k = 1, #gradInputSucc do
-               if gi then
-                  gi:add(gradInputSucc[k])
-               else
-                  gi = gradInputSucc[k]:clone()
-               end
-            end
-         end
-         nnm:updateGradInput(node.input, gi)
+         nnm:updateGradInput(node.input, self:computeGradInput(gradInputSucc))
       end
 
       -- We fill the gradInputSucc of our predecessors

diff --git a/test-dagnn.lua b/test-dagnn.lua
index 32eed57..d7179cc 100755 (executable)
--- a/test-dagnn.lua
+++ b/test-dagnn.lua
@@ -58,6 +58,6 @@ printTensorTable(output)
 print('******************************************************************')
 print('** updateGradInput ***********************************************')
 print('******************************************************************')
-gradInput = g:updateGradInput({ input }, output)
+gradInput = g:updateGradInput({{input}}, output)
 
 printTensorTable(gradInput)