Armadillo with lapack and blas on Qt (Ubuntu 14.10)

Qt-Armadillo-Ubuntu

When trying to use armadillo with Qt in ubuntu, follow this steps:

1- Open synaptic.

2- Search for libarmadillo4 and libarmadillo-dev, if they are installed, mark for uninstall, apply.

3- Search for libblas3 and liblapack3 and mark both libs to reinstall (this will remove a version problem with armadillo), apply.

4- Mark for install liblapack-dev and libblas-dev, apply.

5- Install libarmadillo4 and libarmadillo-dev.

6- Open Qt (tested with version 5.4) and create a new console application.

7- In main.cpp, paste the following code:

#include <armadillo>
#include <iostream>

using namespace std;
using namespace arma;

int main()
{
  vec b;
  b << 2.0 << 5.0 << 2.0;
  
  mat A;
  A << 1.0 << 2.0 << endr
    << 2.0 << 3.0 << endr
    << 1.0 << 3.0 << endr;

  cout << "Least squares solution:" << endl;
  cout << solve(A,b) << endl;

  return 0;
}

8- In the .pro file, add: LIBS += -llapack -lblas -larmadillo

9- Compile, run and test the application.