# A very simple tutorial about vectors and matrixes

Let's start with a really simple example. Try to complile the following program:

    #include <itpp/itbase.h>

    using namespace itpp;

    //These lines are needed for use of cout and endl
    using std::cout;
    using std::endl;

    int main()
    {
      //Declare vectors and matricies:
      vec a, b, c;
      mat A, B;

      //Use the function linspace to define a vector:
      a = linspace(1.0, 2.0, 10);

      //Use a string of values to define a vector:
      b = "0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0";

      //Add two vectors:
      c = a + b;

      //Print results:
      cout << "a = " << a << endl;
      cout << "b = " << b << endl;
      cout << "c = " << c << endl;

      //Use a string to define a matrix:
      A = "1.0 2.0;3.0 4.0";

      //Calculate the inverse of matrix A:
      B = inv(A);

      //Print results:
      cout << "A = " << A << endl;
      cout << "B = " << B << endl;

      //Exit program:
      return 0;

    }

When you run this program, the output shall look like this

    a = [1 1.11111 1.22222 1.33333 1.44444 1.55556 1.66667 1.77778 1.88889 2]
    b = [0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1]
    c = [1.1 1.31111 1.52222 1.73333 1.94444 2.15556 2.36667 2.57778 2.78889 3]
    A = [[1 2]
     [3 4]]
    B = [[-2 1]
     [1.5 -0.5]]

If this is what you see, then congratulations! You have managed to compile your first it++ program!