change several assertions to exception throw to guard it from incorrect behavior under the release build.

change gradient check error information display from stdout to stderr.

DataReader/HTKMLFReader/HTKMLFReader.cpp

@@ -1425,12 +1425,10 @@ namespace Microsoft { namespace MSR { namespace CNTK {
 		switch (endDataType)
 		{
 		case endDataNull:
-			assert(false);
-			break;
 		case endDataEpoch:
 		case endDataSet:
-			assert(false); // not support
-			break;
+            throw std::logic_error("DataEnd: does not support endDataTypes: endDataNull, endDataEpoch and endDataSet");
+            break;
 		case endDataSentence:
 			if (m_truncated)
 				ret = m_sentenceEnd[0];

MachineLearning/CNTKEval/EvalWriter.h

@@ -78,6 +78,7 @@ public:
     virtual void GetSections(std::map<std::wstring, SectionType, nocase_compare>& /*sections*/) 
     {
         assert(false);
+        NOT_IMPLEMENTED;
     }
     virtual bool SaveData(size_t /*recordStart*/, const std::map<std::wstring, void*, nocase_compare>& matrices, size_t numRecords, size_t /*datasetSize*/, size_t /*byteVariableSized*/)
     {

MachineLearning/cn/ComputationNode.h

@@ -828,11 +828,11 @@ namespace Microsoft { namespace MSR { namespace CNTK {
         }
 
         virtual ComputationNodePtr Duplicate(const std::wstring& newName, const CopyNodeFlags flags) const = 0;
-        virtual TaskDescriptor<ElemType>* GetPTaskDescriptor(TaskType /*taskType*/, size_t inputIndex=0) const
+        virtual TaskDescriptor<ElemType>* GetPTaskDescriptor(TaskType /*taskType*/, size_t /*inputIndex=0*/) const
         {
-            inputIndex;
             assert(false);
-            return NULL;
+            NOT_IMPLEMENTED;
+            //return NULL;
         }
     protected:
 

MachineLearning/cn/SGD.h

@@ -1347,7 +1347,7 @@ protected:
                 bool wrong = (_isnan(diff) || diff > threshold);
                 if (wrong)
 				{
-                    fprintf (stdout, "\nd%ws Numeric gradient = %e, Error BP gradient = %e\n", node->NodeName().c_str(), eGradNum, eGradErr);
+                    fprintf (stderr, "\nd%ws Numeric gradient = %e, Error BP gradient = %e\n", node->NodeName().c_str(), eGradNum, eGradErr);
                     return false; 
 				}
             }

MachineLearning/cn/SynchronousExecutionEngine.h

@@ -764,8 +764,7 @@ protected:
     // Copy constructor, should never be called.
     SynchronousExecutionEngine(const SynchronousExecutionEngine<ElemType>& /*deepCopyFrom*/) 
     {         
-        assert(false);
-        //throw std::logic_error("'SynchronousExecutionEngine(const SynchronousExecutionEngine<ElemType>& deepCopyFrom)' should never be called.");
+        throw std::logic_error("'SynchronousExecutionEngine(const SynchronousExecutionEngine<ElemType>& deepCopyFrom)' should never be called.");
     } 
 
     // Assignment operator, should never be called.