I can't get this to compile:
Eigen::Map<Eigen::Matrix<const T, EA::ColsAtCompileTime, 1>> x(vec);
auto result = a_ * x - b_; // a(60r,1200c) * x(1200r,1c) - b(60r,1c)
The two errors (about 1000 lines each) eventually conclude that the * and - operators can't be "overloaded" (their term, not mine).
a_ is of this type: typedef Eigen::Map<Eigen::Matrix<double, ROWS, COLS>> EA;
b_ is of this type: typedef Eigen::Map<Eigen::Matrix<double, ROWS, 1>> EB;
T is the Ceres Solver Jet type. The errors seem to bespeak a column/row mismatch rather than a type problem. I could be wrong, though; the output is entirely too verbose. Did I misunderstand how the rows and columns work with Eigen matrix operators?
Update: I followed the "fatal-errors" suggestion:
In file included from /usr/include/eigen3/Eigen/Core:437:0,
from /usr/local/include/ceres/jet.h:165,
from /usr/local/include/ceres/internal/autodiff.h:145,
from /usr/local/include/ceres/autodiff_cost_function.h:132,
from /usr/local/include/ceres/ceres.h:37,
from /home/brannon/Workspace/Solver/music_solver.cpp:3:
/usr/include/eigen3/Eigen/src/Core/PlainObjectBase.h: In instantiation of ‘class Eigen::PlainObjectBase<Eigen::Matrix<const double, 1200, 1, 0, 1200, 1> >’:
/usr/include/eigen3/Eigen/src/Core/Matrix.h:178:7: required from ‘class Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>’
/usr/include/eigen3/Eigen/src/Core/Map.h:24:32: required from ‘struct Eigen::internal::traits<Eigen::Map<Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>, 0, Eigen::Stride<0, 0> > >’
/usr/include/eigen3/Eigen/src/Core/util/ForwardDeclarations.h:32:54: required from ‘struct Eigen::internal::accessors_level<Eigen::Map<Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>, 0, Eigen::Stride<0, 0> > >’
/usr/include/eigen3/Eigen/src/Core/util/ForwardDeclarations.h:113:75: required from ‘class Eigen::Map<Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>, 0, Eigen::Stride<0, 0> >’
/home/brannon/Workspace/Solver/music_solver.cpp:18:72: required from ‘bool MusicCostFunctor<MATRIX_A, MATRIX_B>::operator()(const T*, T*) const [with T = double; MATRIX_A = Eigen::Map<Eigen::Matrix<double, 60, 1200, 0, 60, 1200>, 0, Eigen::Stride<0, 0> >; MATRIX_B = Eigen::Map<Eigen::Matrix<double, 60, 1, 0, 60, 1>, 0, Eigen::Stride<0, 0> >]’
/usr/local/include/ceres/internal/variadic_evaluate.h:175:19: required from ‘static bool ceres::internal::VariadicEvaluate<Functor, T, N0, 0, 0, 0, 0, 0, 0, 0, 0, 0>::Call(const Functor&, const T* const*, T*) [with Functor = MusicCostFunctor<Eigen::Map<Eigen::Matrix<double, 60, 1200, 0, 60, 1200>, 0, Eigen::Stride<0, 0> >, Eigen::Map<Eigen::Matrix<double, 60, 1, 0, 60, 1>, 0, Eigen::Stride<0, 0> > >; T = double; int N0 = 1200]’
/usr/local/include/ceres/autodiff_cost_function.h:208:17: required from ‘bool ceres::AutoDiffCostFunction<CostFunctor, kNumResiduals, N0, N1, N2, N3, N4, N5, N6, N7, N8, N9>::Evaluate(const double* const*, double*, double**) const [with CostFunctor = MusicCostFunctor<Eigen::Map<Eigen::Matrix<double, 60, 1200, 0, 60, 1200>, 0, Eigen::Stride<0, 0> >, Eigen::Map<Eigen::Matrix<double, 60, 1, 0, 60, 1>, 0, Eigen::Stride<0, 0> > >; int kNumResiduals = 1; int N0 = 1200; int N1 = 0; int N2 = 0; int N3 = 0; int N4 = 0; int N5 = 0; int N6 = 0; int N7 = 0; int N8 = 0; int N9 = 0]’
/home/brannon/Workspace/Solver/music_solver.cpp:115:1: required from here
/usr/include/eigen3/Eigen/src/Core/PlainObjectBase.h:585:27: error: ‘static Eigen::PlainObjectBase<Derived>::MapType Eigen::PlainObjectBase<Derived>::Map(Eigen::PlainObjectBase<Derived>::Scalar*) [with Derived = Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>; Eigen::PlainObjectBase<Derived>::MapType = Eigen::Map<Eigen::Matrix<const double, 1200, 1, 0, 1200, 1>, 0, Eigen::Stride<0, 0> >; Eigen::PlainObjectBase<Derived>::Scalar = const double]’ cannot be overloaded
static inline MapType Map(Scalar* data)
^~~
After looking again at this example: https://groups.google.com/d/msg/ceres-solver/7ZH21XX6HWU/Z3E-k2fbAwAJ
I realized that I put the const in the wrong spot. It's supposed to be Map<const... rather than <const T.