Method Identity

include/Eigen/Eigen/src/Core/DiagonalMatrix.h:296–296

    /** Initializes a identity matrix of size SizeAtCompileTime */
    EIGEN_DEVICE_FUNC
    static const InitializeReturnType Identity() { return DiagonalVectorType::Ones().asDiagonal(); }
    /** Initializes a identity matrix of size dim */
    EIGEN_DEVICE_FUNC
    static const InitializeReturnType Identity(Index size) { return DiagonalVectorType::Ones(size).asDiagonal(); }