C# Random of cordinates is linear

c#

Solution

Jørn's answer gave the problem, but not the solution: just use a single instance of `Random`:

Random rng = new Random();

for (int i = 0; i < 50; i++)
{
    int lat = rng.Next(516400146, 630304598);
    int lon = rng.Next(224464416, 341194152);
    SamplePostData d0 = new SamplePostData();
    d0.Location = new Location(18d + lat / 1000000000d,
                               -72d - lon / 1000000000d);
    AddPushpin(d0);
}

(I've changed the way of using the result, too - there's no need to convert to and from a string to achieve what you want. An alternative would be to call `Random.NextDouble` instead and multiply it by the size of the desired range, then add a base value.)

If you're calling routine multiple times, you should probably use a single instance of `Random` across those multiple calls. Beware though: `Random` in .NET is not thread-safe. Ideally you should have a single instance per thread. See my article on randomness for more details of how to handle `Random`.

Problem

My code is to generate random cordinates of lat and long within a bound: ``` Random lastLat = new Random(); Random lastLon = new Random(); for (int i = 0; i < 50; i++) { int lat = lastLat.Next(516400146, 630304598); //18.51640014679267 - 18.630304598192915 int lon = lastLon.Next(224464416, 341194152); //-72.34119415283203 - -72.2244644165039 SamplePostData d0 = new SamplePostData(); d0.Location = new Location(Convert.ToDouble("18." + lat), Convert.ToDouble("-72." + lon)); AddPushpin(d0); } ``` My output looks like this: http://img263.imageshack.us/img263/7504/capturerkv.png http://img263.imageshack.us/img263/7504/capturerkv.png Is there something wrong with how my numbers are generated?

Original source