C++ Tensor::Dims方法代码示例

void Tensor::Divide(Tensor& result_tensor, Tensor& t1, double val)
{
	result_tensor.Initialize(t1.Dims());

	for (int i = 0; i < t1.NumElements(); ++i)
	{
		result_tensor.Set(i, t1.At(i) / val);
	}
}

// add two tensors, store result in result_tensor which is assumed 
// to be uninitialized
void Tensor::Add(Tensor& result_tensor, Tensor& t1, Tensor& t2)
{
	assert(t1.NumElements() == t2.NumElements());
	result_tensor.Initialize(t1.Dims());

	for (int i = 0; i < result_tensor.NumElements(); ++i)
	{
		result_tensor.Set(i, t1.At(i) + t2.At(i));
	}
}

void Tensor::Rearrange(Tensor& result_tensor, Tensor& orig_tensor, vector<int>& old_to_new_modes)
{
	vector<int> new_dims;
	VectorPlus::Rearrange(new_dims, orig_tensor.Dims(), old_to_new_modes);

	result_tensor.Initialize(new_dims);

	int i = 0;
	FastIndexer indexer(orig_tensor.Dims());
	while (indexer.HasNext())
	//for (int i = 0; i < orig_tensor.NumElements(); ++i)
	{
		vector<int>& orig_indices = indexer.GetNext();
//		vector<int> orig_indices;
//		orig_tensor.ComputeIndexArray(orig_indices, i);
		vector<int> new_indices;
		VectorPlus::Rearrange(new_indices, orig_indices, old_to_new_modes);

		result_tensor.Set(new_indices, orig_tensor.At(i++));
	}
}

	vector<int>& Dims() { return prob_tensor->Dims(); }

void Tensor::CreateLinearSystem(vector<double>& B_vec, Matrix& A_matrix, 
						Tensor& X, Tensor& A, Tensor& B,
						vector<int>& mult_modesX, vector<int>& mult_modesA)
{
	// fake multiply x and A together to create B, creating the linear system in the process

	assert(mult_modesX.size() == mult_modesA.size());

	if (X.Order() == mult_modesX.size() && A.Order() == mult_modesA.size())
	{
		assert(0);
	}

	int numMultElements = 1;	
	vector<int> mult_dims(mult_modesX.size(), 0);

	for (int i = 0; i < mult_modesX.size(); ++i) 
	{
		assert(X.Dim(mult_modesX[i]) == A.Dim(mult_modesA[i]));
		mult_dims[i] = X.Dim(mult_modesX[i]);
		numMultElements = numMultElements * mult_dims[i];
	}
	vector<int> mult_offsets;
	ComputeOffsets(mult_offsets, mult_dims);
	int result_order = X.Order() + A.Order() - mult_modesX.size() - mult_modesA.size(); 

	if (result_order == 0)
		assert(0);

	vector<int> result_dims;

	vector<int> free_modesX;
	vector<int> free_modesA;


	// find free indices from X
	for (int i = 0; i < X.Order(); ++i)
	{
		if (!VectorPlus::Contains(mult_modesX, i))
		{
			free_modesX.push_back(i);
		}
	}

	// find free indices from A
	for (int i = 0; i < A.Order(); ++i)
	{
		if (!VectorPlus::Contains(mult_modesA, i))
		{
			free_modesA.push_back(i);
		}
	}
	vector<int> a_mat_dims = VectorPlus::CreatePair(B.NumElements(), X.NumElements());
	A_matrix.Initialize(a_mat_dims);
	B_vec.reserve(B.NumElements());
	// fill in elements from result tensor

	FastIndexer B_indexer(B.Dims());

	for (int n = 0; n < B.NumElements(); ++n)
	{
		B_vec.push_back(B.At(n));

		vector<int>& indices = B_indexer.GetNext();
		vector<int> free_indicesX;
		vector<int> free_indicesA;
	//	B.ComputeIndexArray(indices, n);

		for (int i = 0; i < B.Order(); ++i)
		{
			if (!VectorPlus::Contains(mult_modesX, i))
				free_indicesX.push_back(indices[i]);
			else
				free_indicesA.push_back(indices[i]);
		}

		// sum over elementwise products of mult-mode elements
		double temp_sum = 0;
		FastIndexer mult_indexer(mult_dims);
		for (int k = 0; k < numMultElements; ++k)
		{
			vector<int>& mult_indices = mult_indexer.GetNext();
		//	ComputeIndexArray(mult_indices, mult_offsets, k);

			vector<int> indicesX; 
			vector<int> indicesA;

			MergeIndices(indicesX, mult_modesX, free_modesX, mult_indices, free_indicesX);
			MergeIndices(indicesA, mult_modesA, free_modesA, mult_indices, free_indicesA);

			
			A_matrix.Set(n, X.ComputeIndex(indicesX), A.At(indicesA));
		}
	}
}