Function SumColumns

src/core/tensor/tensor.cc:1508–1522

void SubRow(const Tensor &v, Tensor *M) { AddRow(-1, 1, v, M); }

void SumColumns(const Tensor &M, Tensor *v) {
  if (M.transpose()) {
    Tensor X = Transpose(M);
    SumRows(X, v);
  } else {
    CHECK_EQ(M.nDim(), 2u);
    // CHECK_EQ(v->nDim(), 1u); (chonho) shape of v is 2-element tuple
    size_t nb_row = M.shape().at(0), nb_col = M.shape().at(1);
    CHECK_EQ(nb_row, v->Size());

    Tensor one(Shape{nb_col}, M.device(), M.data_type());
    one.SetValue(1.0f);  // TODO(wangwei) cast type
    Mult(M, one, v);
  }
}
void SumRows(const Tensor &M, Tensor *v) {
  if (M.transpose()) {
    Tensor X = Transpose(M);