So the way to fix this which took me an annoyingly long time to find is to use the derived cast method described here. Now the definition is this: internal::cast_return_type<Derived,const CwiseUnaryOp<internal::scalar_cast_op<typenameinternal::traits<Derived>::Scalar, NewType>, const Derived> >::type cast() const Which Ill admit, phased me a little. But turns out it is pretty easy (and the only explanation … Read more
1. Install Homebrew • Package manager for Mac, allows you to download pretty much anything with one Terminal command. Follow steps here. 2. Install Eigen • Simply run the following command in Terminal: brew install eigen • Eigen is now installed. • Make note of the file path that is printed out on the command … Read more
The best way to solve a system of linear equations of the form Ax = b is to do the following. decompose A into the format A = M1 * M2 (where M1 and M2 are triangular) Solve M1 * y = b for y using back substitution Solve M2 * x = y for … Read more
You want .norm(). Note that there’s also .squaredNorm(), .normalized() and .normalize().
It looks like a problem of GCC. Intel compiler gives the expected result. $ g++ -I ~/program/include/eigen3 -std=c++11 -O3 a.cpp -o a && ./a test1_us: 200087 test2_us: 320033 test3_us: 44539 $ icpc -I ~/program/include/eigen3 -std=c++11 -O3 a.cpp -o a && ./a test1_us: 214537 test2_us: 23022 test3_us: 42099 Compared to the icpc version, gcc seems to … Read more
Found in the documentation :/ The way to access a single column is .col(i), and similarly for row, its .row(i). Also of interest is .block<>.
This answer is only a summary from the comments above: At compile-time you have EIGEN_WORLD_VERSION, EIGEN_MAJOR_VERSION and EIGEN_MINOR_VERSION, you can easily embed this information in your application. 3.1.91 sounds like a beta version of 3.2. The version number macros are defined in Macros.h located at \Eigen\src\Core\util\.
Since Eigen3 is completely header only, all you ever need is the path to the include directory. And this one, you are already defining manually anyway. So there is no real need for a FindEigen3.cmake or FIND_PACKAGE call. Simply use INCLUDE_DIRECTORIES ( “$ENV{EIGEN3_INCLUDE_DIR}” ) or SET( EIGEN3_INCLUDE_DIR “$ENV{EIGEN3_INCLUDE_DIR}” ) IF( NOT EIGEN3_INCLUDE_DIR ) MESSAGE( FATAL_ERROR … Read more
You can also use void eigen2cv(const Eigen::Matrix<_Tp, _rows, _cols, _options, _maxRows, _maxCols>& src, Mat& dst) and void cv2eigen(const Mat& src, Eigen::Matrix<_Tp, _rows, _cols, _options, _maxRows, _maxCols>& dst) from #include <opencv2/core/eigen.hpp>.
In general, using a non const reference like Ref<T>& is never a good idea because this will only work if the caller already has a Ref<T> object at hand. This discards 5 and 7. The cases 3 and 4 does not make sense, and they won’t compile in general. Then, there is not much difference … Read more