add LogSoftmax

source/tensor/function/LogSoftmax.cpp

@@ -20,9 +20,10 @@
 */
 
 #include <math.h>
-#include "../XUtility.h"
 #include "LogSoftmax.h"
 #include "LogSoftmax.cuh"
+#include "../XName.h"
+#include "../XUtility.h"
 #include "../core/reduce/ReduceSum.h"
 #include "../core/reduce/ReduceMax.h"
 #include "../core/movement/CopyValues.h"
@@ -161,6 +162,25 @@ void _LogSoftmax(const XTensor * x, XTensor * y, int leadDim)
 }
 
 /* 
+log scale softmax y = log(e^x / \sum_{i} e^{x_i}) (return a structure) 
+>> x - input vector
+>> leadDim - leading dimension (along which we perform reduction)
+<< return - result
+*/
+XTensor LogSoftmax(const XTensor &x, int leadDim)
+{
+    XTensor y(&x);
+    y.SetTMP();
+
+    _LogSoftmax(&x, &y, leadDim);
+
+    XLink::MakeLink(&x, NULL, &y, FUNC_LOGSOFTMAX);
+    XLink::AddParamToHeadInt(&y, leadDim);
+
+    return y;
+}
+
+/*
 backward computation for dense matrices with default data type
 
 dE/dx = dE/dy * dy/dx

source/tensor/function/LogSoftmax.h

@@ -30,6 +30,9 @@ namespace nts{ // namespace nts(NiuTrans.Tensor)
 /* log scale softmax y = log(e^x / \sum_{i} e^{x_i}) */
 void _LogSoftmax(const XTensor * x, XTensor * y, int leadDim);
 
+/* log scale softmax y = log(e^x / \sum_{i} e^{x_i}) (return a structure) */
+XTensor LogSoftmax(const XTensor &x, int leadDim);
+
 /* de/dx */
 void _LogSoftmaxBackward(XTensor * gold, XTensor * y, XTensor * x, 
                          XTensor * dedy, XTensor * dedx,