declare XNet class

source/network/Main.cpp

@@ -40,6 +40,10 @@ int main( int argc, const char ** argv )
         fprintf(stderr, "Run this program with \"-test\" for unit test!\n");
     }
 
+    XNet net;
+    XTensor a;
+    net.Backward(a);
+    
     //_CrtDumpMemoryLeaks();
     
     return 0;

source/network/XNet.cpp

@@ -23,4 +23,67 @@
 
 namespace nts{
 
+/* constructor */
+XNet::XNet()
+{
+    nodes.Clear();
+}
+
+/* de-constructor */
+XNet::~XNet()
+{
+}
+
+/* 
+backward propagation to obtain gradient wrt. the loss/error function 
+>> root - root node (output) of the network
+>> gold - gold standard for the output
+>> loss - name of loss function
+*/
+void XNet::Backward(XTensor &root, XTensor &gold, LOSS_FUNCTION_NAME loss)
+{
+    XList roots(1);
+    roots.Add(&root);
+
+    XList golds(1);
+    golds.Add(&gold);
+
+    Backward(roots, golds, loss);
+}
+
+/* 
+backward propagation to obtain gradient wrt. the loss/error function
+with a number of root nodes 
+>> root - a list of root nodes (output) of the network
+>> gold - a list of gold standard for the output
+>> loss - name of loss function
+*/
+void XNet::Backward(XList &roots, XList &golds, LOSS_FUNCTION_NAME loss)
+{
+    Traverse(roots);
+}
+
+/* 
+traverse the net and find the topological order by 
+depth-first search (Tarjan's algorithm) 
+>> root - root node (or output of the net)
+*/
+void XNet::Traverse(XTensor &root)
+{
+    XList roots(1);
+    roots.Add(&root);
+
+    Traverse(roots);
+}
+
+/* 
+traverse the net and find the topological order by 
+depth-first search (Tarjan's algorithm) 
+>> roots - a list of roots (or output nodes)
+*/
+void XNet::Traverse(XList &roots)
+{
+    nodes.Clear();
+}
+
 }
\ No newline at end of file

source/network/XNet.h

@@ -30,9 +30,16 @@
 namespace nts{
 
 /* management of tensor net (or graph) */
-class XNet
+struct XNet
 {
-public:
+    /* tensor nodes of the net (in order) */
+    XList nodes;
+
+    /* constructor */
+    XNet();
+
+    /* de-constructor */
+    ~XNet();
 
     /* backward propagation to obtain gradient wrt. the loss/error function */
     void Backward(XTensor &root, XTensor &gold = NULLTensor, LOSS_FUNCTION_NAME loss = NOLOSS);
@@ -40,6 +47,14 @@ public:
     /* backward propagation to obtain gradient wrt. the loss/error function
        with a number of root nodes */
     void Backward(XList &roots, XList &golds = NULLList, LOSS_FUNCTION_NAME loss = NOLOSS);
+
+    /* traverse the net and find the topological order by 
+       depth-first search (Tarjan's algorithm) */
+    void Traverse(XTensor &root);
+
+    /* traverse the net and find the topological order by 
+       depth-first search (Tarjan's algorithm) */
+    void Traverse(XList &roots);
 };
 
 }

source/tensor/Main.cpp

@@ -45,7 +45,7 @@ int main( int argc, const char ** argv )
     //_CrtSetBreakAlloc(123);
 
     /* a tiny test */
-    if(false)
+    if(true)
         SmallTest();
 
     //_CrtDumpMemoryLeaks();

source/tensor/XLink.cpp

@@ -37,6 +37,7 @@ XLink::XLink()
     paramNum = 0;
     type[0] = 0;
     typeID = 0;
+    caculator = NULL;
 }
     
 /* deconstructor */
@@ -59,6 +60,8 @@ void XLink::Reset()
     tailNum  = 0;
     paramNum = 0;
     type[0]  = 0;
+    typeID   = 0;
+    caculator = NULL;
 }
 
 /* clear it */
@@ -68,6 +71,8 @@ void XLink::Clear()
     tailNum  = 0;
     paramNum = 0;
     type[0]  = 0;
+    typeID   = 0;
+    caculator = NULL;
 }
 
 /* reset tails */

source/tensor/XLink.h

@@ -77,6 +77,9 @@ struct XLink
     /* type id */
     int typeID;
 
+    /* caculator (pointer to the class for computation) */
+    void * caculator;
+    
     /* constuctor */
     XLink();