How to use Qvector<Qvector <double> as matrix?

Question

In the mainwindow.h have:

private:
QVector<QVector<double> > numbers; //Variável que será minha matriz
public slot:
void realizar_calcs(QVector<QVector<double> > &numbers);

In the mainwindow.cpp

void MainWindow::realizar_calcs(QVector<QVector<double> > &numbers)
{
   int n1 = 10;
   numbers.resize(n1);
   for(int i = 0;i < n1;i++)
   {
      numbers[i].resize(n2);
   }
}

My difficulty is in its initialization and the passage to function!

Answer 1

An array is not meant to behave like an array. Of course there are some solutions.

I found a solution that seems to approach what you want, see if it helps. It shows how to initialize the vector as if it were a matrix.

There is a class in Qt for this but it was considered obsolete and as far as I know nothing was created to replace it. but it has a more modern class in version 4.6 onwards.

Another obvious option is to look for a class that serves you in another library. It might not be as simple to integrate with Qt.

There is still the possibility of creating a class of your own that works as a matrix. This can bring some advantages of integration with Qt depending on how you do it.

I found a gambit in that reply in the OS:

int index(int x, int y) {
    return x + width * y;
}

So you simulate a matrix within the vector:

QVector<...> vector(width * height);
vector[index(5, 3)] = ...;

I put in the Github for future reference.