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c++matrixeigenbazeleigen3

Bazel gives compilation error when converting matrix types

I am using bazel to build some code. The code gives compilation error while doing dome matrix assignments.

typedef Eigen::Matrix<double,44,44> stateMat_t;
typedef Eigen::Matrix<double,44,44> stateTens_t[44];   //44 x 44 x 44


// bunch of other code...

typedef std::vector<stateMat_t> stateTensTab_t;

// bunch of other code...

stateTensTab_t fxxList;
stateTens_t fxx;

// bunch of other code

fxxList[j][k] = fxx[j];

//bunch of other code

I expect the code to compile successfully, but it gives the following error:

error: cannot convert 'Eigen::Matrix<double, 44, 44>' to 'Eigen::DenseCoeffsBase<Eigen::Matrix<double, 44, 44>, 1>::Scalar {aka double}' in assignment
                     fxxList[j][k] = fxx[j];
Solution

  • You are trying to assign a Matrix<double,44,44> to a double&, since that is what Matrix::operator[] returns (the operator where you pass k). Calling that operator alone should also fail, since stateMat_t is not a vector at compile time.