eigen Questions
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I've been successfully using cppyy for automatic python bindings for a C++ project I'm working on. I recently included the Eigen library, but I'm having trouble using this together with cppyy. Does...
Enterovirus asked 17/12, 2018 at 15:59
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Is there an easy way to evaluate the column wise dot product of 2 matrices (lets call them A and B, of type Eigen::MatrixXd) that have dimensions mxn, without evaluating A*B or without having to re...
Krp asked 20/11, 2014 at 2:11
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I have seen it done before but I cannot remember how to efficiently initialize an Eigen::Vector of known length with a std::vector of the same length. Here is a good example:
std::vector<double...
0
Recently I am using Eigen library for a project. I’m curious why there’s no binary file to link, but only a header. I don’t really understand how Eigen works behind the scene to make this possible....
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So I wanted to test the speed of C++ vs Matlab for solving a linear system of equations. For this purpose I create a random system and measure the time required to solve it using Eigen on Visual St...
Exegetics asked 11/11, 2018 at 8:37
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In Eigen, if we have symmetric positive definite matrix A then we can calculate the inverse of A by
A.inverse();
or
A.llt().solve(I);
where I is an identity matrix of the same size as A. But ...
Tumer asked 28/7, 2016 at 15:22
1
Consider the following code.
const int N = 100;
const float alpha = 0.9;
Eigen::MatrixXf myVec = Eigen::MatrixXf::Random(N,1);
Eigen::MatrixXf symmetricMatrix(N, N);
for(int i=0; i<N; i++)
fo...
3
I am used to Eigen for almost all my mathematical linear algebra work.
Recently, I have discovered that Boost also provides a C++ template class library that provides Basic Linear Algebra Library (...
1
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Why Matrix Addition takes much longer than Matrix-Vector Multiplication?
Matrix Add only costs n^2 add, whereas Matrix-Vector Multiplication takes n*(n-1) add and n^2 multiplication.
However, i...
Horoscopy asked 20/9, 2018 at 16:57
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In Matlab there are cond and rcond, and in LAPACK too. Is there any routine in Eigen to find the condition number of a matrix?
I have a Cholesky decomposition of a matrix and I want to check if it...
1
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For the following struct
struct TestClass {
TestClass() : mat(Eigen::Matrix3i::Zero()) {}
Eigen::Matrix3i mat;
};
I would like to have an overloaded operator<< to print the mat member to...
4
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I'm currently working on a MATLAB project and I'd like to re-implement the most computational-heavy parts using C++ and Eigen.
I'd like to know if there's a way to perform the following operation (...
Revisionist asked 24/11, 2012 at 9:57
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I am trying to asign a block of a sparse matrix and canot get it to work. It seems a function used by eigen is deprecated and I could fix it with some definitions. However, I am usure whether or no...
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I wrote a kalman Filter implementation using the Eigen Library in C++ and also using the implementation at this link to test my filter: My prediction step looks like this:
void KalmanFilter::Predi...
Alyosha asked 23/5, 2018 at 15:13
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I am trying to do something as simple as:
std::cout << e << std::endl;
where e is of type Eigen::Affine3d. However, I am getting unhelpful error messages like:
cannot bind 'std::o...
2
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I have an array of 3D points, as a std::vector<Eigen::Vector3d>.
I need to transform these points with a position and quaternion.
My questions are:
How can I rotate these points with a quater...
3
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I'm investigating ways to speed up a large section of C++ code, which has automatic derivatives for computing jacobians. This involves doing some amount of work in the actual residuals, but the maj...
Fin asked 31/8, 2018 at 10:29
4
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I want to read data from a file into a matrix in Eigen. I have coded everything but there is one problem that I encounter. I don't know yet beforehand how many data points are in the file, so I wan...
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UPDATED: I managed to get it to work after I googled around and read the doxygen comments in code. Problem was that I missed the cast before using resize() method and also not using std::ios::binar...
Parotid asked 5/4, 2014 at 17:26
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In Eigen library's official cmake doc, it requires the line target_link_libraries (example Eigen3::Eigen). I have tried removing that line, but then the compilation would fail with "Eigen not found...
1
I am doing a lot of matrix multiplications in a C++ program and I use Eigen (3.3.5) linked with Intel's MKL (2018.3.222). I use the sequential version of the MKL and OpenMP is disabled. The problem...
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So I was wondering if it is possible to set a static variable inside a function scope only once. For example consider this function:
void projectPointIntoPlane(const Affine3f& plane2xy, Vector...
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Probably a dumb / simple question, but I have not been able to find an answer. I have no clue how adding libraries works with CodeBlocks c++. I downloaded the .zip file from http://eigen.tuxfamily....
Save asked 13/4, 2016 at 20:30
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I am trying to estimate how good is Python performance comparing to C++.
Here is my Python code:
a=np.random.rand(1000,1000) #type is automaically float64
b=np.random.rand(1000,1000)
c=np.empty...
Titulary asked 2/8, 2018 at 15:3
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I think Eigen uses compressed methods to store sparse matrices. Is there any way that I can extract Triplet-format vectors of an Eigen sparse matrix in from of std::vectors?
Thanks.
More info (an...
Brasier asked 23/2, 2015 at 23:55
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