armadillo

问题 This question already has answers here : use std::fill to populate vector with increasing numbers (14 answers) Closed 3 years ago . I would like to create a row vector in C++ with integer elements from and including 0 to N (an integer variable I assign in my C++ program). I have seen the Armadillo C++ library and tried using its span function but it does not create a vector (rather creates an object with type arma::span ) so writing: vec n = span(0,N); does not create the desired vector. If

问题 I'm trying to multiply a sparse real matrix with a complex vector but the program does not compile. If I change the vector to real or the matrix to dense, then everything goes through. A sample code is: #define ARMA_64BIT_WORD #include <armadillo> #include <iostream> #include <stdio.h> #include <math.h> using namespace arma; int main(){ size_t n(5); vec vR(randu<vec>(n)), vI(randu<vec>(n)); //Create random complex vector 'v' cx_vec v(vR, vI); std::cout<<"\n\tMultiplying real matrix with

问题 I need to install and use Armadillo library to deal with linear algebra . I went to their websites and downloaded .tar.xz file, but I have no idea how to install it. How can I install Armadillo ? (I'm primarily using Dev-C++ , but I also sometimes use XCode ) 回答1: If you are using Windows, you might be using Visual Studio for compilation. Extract tarball using 7zip or other extraction software and save it in the directory of your choice. For example your path could be, C:\armadillo . In the

问题 I'm trying to wrap a c++ function that uses Armadillo library using pybind11 and cppimport . But when I try to do something simple like matrix multiplication I get the following error. error: no matching function for call to ‘pybind11::buffer_info::buffer_info(double*, long unsigned int, std::__cxx11::string, int, <brace-enclosed initializer list>, <brace-enclosed initializer list>)’ ); ^ In file included from /home/muah/anaconda3/envs/ising/include/python3.6m/pybind11/pytypes.h:13:0, from

问题 What would be the most efficient (i.e. balance memory and speed) way to access the upper or lower triangular elements of an Armadillo matrix? I know I could provide a vector of integers for the elements but as matrices become very large I would like avoid carrying around another large vector. Or is there an efficient way to quickly create the lower/upper triangular indices? For example with a 5x5 matrix // C++11 Initialization arma::mat B = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,

问题 I am going to compile C++ program which contains Armadillo library. This issue is feasible via command line with this command: g++ '/arm.cpp' -o example -O1 -larmadillo But when I add -O1 -larmadillo to the compile options of my NetBeans project I get a considerable amount of errors. I got these errors: "/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf make[1]: Entering directory `/home/atx/NetBeansProjects/armadillo' "/usr/bin/make" -f nbproject/Makefile-Debug.mk

问题 I have a simple example class. It has one data member, which is a std::vector of pointers to armadillo matrices. the constructor takes such a vector as the only argument. here's file TClass.cpp : #include <armadillo> #include <vector> class TClass { private: std::vector<arma::mat * > mats; public: TClass(std::vector<arma::mat * > m_); arma::mat * GetM( int which ){ return( mats.at(which) );}; }; TClass::TClass(std::vector<arma::mat * > m_){ mats = m_; } I want to construct a GTest fixture to

问题 I want to extract linear combinations from matrices but by performing combinations in modulus. Let us consider the calculation modulus 5, we then have the following for the addition: + | 0 1 2 3 4 --+----------- 0 | 0 1 2 3 4 1 | 1 2 3 4 0 2 | 2 3 4 0 1 3 | 3 4 0 1 2 4 | 4 0 1 2 3 and this table for the multiplication: * | 0 1 2 3 4 --+----------- 0 | 0 0 0 0 0 1 | 0 1 2 3 4 2 | 0 2 4 1 3 3 | 0 3 1 4 2 4 | 0 4 3 2 1 So let us take an example: Let us consider the following matrix: E = 2 1 3 2

问题 I want to extract linear combinations from matrices but by performing combinations in modulus. Let us consider the calculation modulus 5, we then have the following for the addition: + | 0 1 2 3 4 --+----------- 0 | 0 1 2 3 4 1 | 1 2 3 4 0 2 | 2 3 4 0 1 3 | 3 4 0 1 2 4 | 4 0 1 2 3 and this table for the multiplication: * | 0 1 2 3 4 --+----------- 0 | 0 0 0 0 0 1 | 0 1 2 3 4 2 | 0 2 4 1 3 3 | 0 3 1 4 2 4 | 0 4 3 2 1 So let us take an example: Let us consider the following matrix: E = 2 1 3 2

问题 I am building an image processing application using OpenCV. I am also using the Armadillo library because it has some very neat matrix related functions. The thing is though, in order to use Armadillo functions on cv::Mat I need frequent conversions from cv::Mat to arma::Mat . To accomplish this I convert the cv::Mat to an arma::Mat using a function like this arma::Mat cvMat2armaMat(cv::Mat M) { copy cv::Mat data to a arma::Mat return arma::Mat } Is there a more efficient way of doing this?