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));
}
}
}