为什么将张量op（sqrt（））与linear.constant（）相乘是不合法的
Eigen::Tensor<float, 1> linear(2);
linear.setValues({3,4});
auto linear_square = linear * linear;
auto linear_square_sum = linear_square.sum().sqrt();
std::cout<<linear_square_sum<<std::endl; // 5
auto new_linear = linear_square_sum * linear.constant(5); //no compiling error but aborted when executing
错误信息
tensor2matrix： /usr/local/include/unsupported/Eigen/CXX11/src/Tensor/TensorEvaluator.h:380： Eigen :: TensorEvaluator，Device> :: TensorEvaluator（const XprType＆， const Device＆）[with BinaryOp = Eigen :: internal :: scalar_product_op; LeftArgType =常量 Eigen :: TensorCwiseUnaryOp， const Eigen :: TensorReductionOp， const Eigen :: DimensionList，const Eigen :: TensorCwiseBinaryOp，常量Eigen :: Tensor，常量Eigen :: Tensor
，Eigen :: MakePointer>>; RightArgType = const Eigen :: TensorCwiseNullaryOp， const Eigen :: Tensor>;设备= Eigen :: DefaultDevice; Eigen :: TensorEvaluator，Device> :: XprType = Eigen :: TensorCwiseBinaryOp，const Eigen :: TensorCwiseUnaryOp， const Eigen :: TensorReductionOp， const Eigen :: DimensionList，const Eigen :: TensorCwiseBinaryOp，const Eigen :: Tensor，const Eigen :: Tensor ，Eigen :: MakePointer>>，const Eigen :: TensorCwiseNullaryOp， const Eigen :: Tensor>>]：断言 `dimensions_match（m_leftImpl.dimensions（），m_rightImpl.dimensions（））' 失败了中止
答案 0 :(得分：0)
我敢肯定，人们已经链接到您的文档，说将auto与表达式模板一起使用不是一个好主意。多次评估一个表达模板似乎是个更糟糕的主意。
如果您不想/不能明确提及类型，可以将它们基于您输入的原始值。
Eigen::Tensor<float, 1> linear(2);
linear.setValues({ 3,4 });
decltype(linear) linear_square = linear * linear;
Eigen::Tensor<decltype(linear)::Scalar, 0> linear_square_sum = linear_square.sum().sqrt();
std::cout << linear_square_sum << std::endl; // 5
// Don't forget to convert to an actual scalar
// |
// v
decltype(linear) new_linear = linear_square_sum() * linear.constant(5);
std::cout << new_linear;
return 0;