Improving the quality of random number generation in Qt 5.3

Question

I am currently implementing a random number generator in Qt5.3 as part of genetic algorithm experiments. I have tried several methods but the best seems to be:

  // Seed the random generator with current time
  QTime time = QTime::currentTime();
  qsrand((uint)time.msec());

And then this funtion to generate the random numbers:

int MainWindow::getRandomNo(int low, int high)
{
    return qrand() % ((high + 1) - low) + low;
}

Because of the nature of these experiments, the random nature of these numbers is important. Is there a way to improve the quality of the random number samples? Upon statistical analysis, the Qt random number generator exhibits typical patterns that are found in older systems of random number generation.

The method used above relies on the current time as a seed for the number generator. Is there a way to improve the seed so that the random sequences are less prone to patterns? I would be extremely grateful for any help.

Answer 1

Use MT.

You can get an implementation here:

• http://www.agner.org/random/
• http://de.wikipedia.org/wiki/Mersenne-Twister
• boost_random

I ran into the same problem years ago in a delphi software, and switching to MT sovled my problem. But check the list in the boost docu for further detailed information about the differences between RNG algorithms.