Adding necessary functions for Loss modules.

- log, flat, moddims
arrayfire · Jul 27, 2017 · dd40725 · dd40725
1 parent 1288a3e
commit dd40725
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diff --git a/include/af/autograd/Functions.hpp b/include/af/autograd/Functions.hpp
@@ -8,6 +8,7 @@
  ********************************************************/
 #pragma once
 
+#include <arrayfire.h>
 #include <vector>
 
 namespace af {
@@ -48,6 +49,7 @@ namespace af {
         Variable reciprocal(const Variable &input);
 
         Variable exp(const Variable &input);
+        Variable log(const Variable &input);
         Variable sin(const Variable &input);
         Variable cos(const Variable &input);
         Variable tanh(const Variable &input);
@@ -73,6 +75,9 @@ namespace af {
         Variable matmulTN(const Variable &lhs, const Variable &rhs);
         Variable matmulNT(const Variable &lhs, const Variable &rhs);
 
+        Variable abs(const Variable &input);
 
+        Variable flat(const Variable &input);
+        Variable moddims(const Variable &input, const dim4 &dims);
     }
 }
diff --git a/src/autograd/Functions.cpp b/src/autograd/Functions.cpp
@@ -194,6 +194,15 @@ namespace af {
             return Variable(result, {input}, grad_func);
         }
 
+        Variable log(const Variable &input)
+        {
+            auto result = log(input.array());
+            auto grad_func = [](std::vector<Variable> &inputs, const Variable &grad_output) {
+                inputs[0].addGrad(grad_output / inputs[0]);
+            };
+            return Variable(result, {input}, grad_func);
+        }
+
         Variable sin(const Variable &input)
         {
             auto result = sin(input.array());
@@ -375,5 +384,35 @@ namespace af {
             };
             return Variable(result, {lhs, rhs}, grad_func);
         }
+
+        Variable abs(const Variable &input)
+        {
+            auto result = af::abs(input.array());
+            auto grad_func = [](std::vector<Variable> &inputs, const Variable &grad_output) {
+                // af::sign returns signbit
+                // Convert it into -1, 1
+                auto sign = Variable(1 - 2 * af::sign(inputs[0].array()), false);
+                inputs[0].addGrad(sign * grad_output);
+            };
+            return Variable(result, {input}, grad_func);
+        }
+
+        Variable flat(const Variable &input)
+        {
+            auto result = af::flat(input.array());
+            auto grad_func = [](std::vector<Variable> &inputs, const Variable &grad_output) {
+                inputs[0].addGrad(moddims(grad_output, inputs[0].dims()));
+            };
+            return Variable(result, {input}, grad_func);
+        }
+
+        Variable moddims(const Variable &input, const dim4 &dims)
+        {
+            auto result = af::moddims(input.array(), dims);
+            auto grad_func = [](std::vector<Variable> &inputs, const Variable &grad_output) {
+                inputs[0].addGrad(moddims(grad_output, inputs[0].dims()));
+            };
+            return Variable(result, {input}, grad_func);
+        }
     }
 }