Need help from a fellow programmer!

[unixknight]

So I wanted to be able to determine configurations and loadouts for my units and experiment with different enemies, so I wrote a program to simulate hand to hand fights between units in Warhammer.

Alright so my program is pretty much done, but there seems to be a problem with the random number generator I'm using in my code. I've thoroughly checked the program and can find no logic errors, yet when I run the following simulation:

Bretonnian MAAs vs. VC Skeletons

The Bretonnians (Assuming a nearby knight) will refuse to charge (fail leadership) 70% of the time when the Skeletons are wielding spears and 85% of the time when the Skeletons have a hand weapon...

And yet the Leadership test has nothing whatsoever to do with the defending unit's weapon choice...

I think what's happening is the cheesy random number generator that comes with .NET is somehow being influenced by this. Either that, or somehow I'm missing something in code.

Anybody have any ideas on where I can get a decent randomizer?

[unixknight]

Alright so predictably, when I put in a fixed seed value it gave me 100% charger wins results.

So when I went back and set a Thread.Sleep(1) in the correct function (gawd)

I now have consistent 79% failure to charge results in both cases of defender weapons.

So it would seem that this pseudo random number generator blows (we knew that) and that the temporary fix is to cripple the program's performance by making it pause for a millisecond every time it rolls dice, which could happen several dozen times in each battle, and I like to run at least a thousand to get a decent statistical average.

So I am still on the lookout for a nicer randomizer to put in my Dice class, but at least this eliminates the rest of the code as being the source of the problem.

[MarginOfError]

So it would seem that this pseudo random number generator blows (we knew that) and that the temporary fix is to cripple the program's performance by making it pause for a millisecond every time it rolls dice, which could happen several dozen times in each battle, and I like to run at least a thousand to get a decent statistical average.

Now I'm confused. If you have a pseudo random number generator (PRNG), why are you making the program pause between rolls? Are you switching from the default PRNG to a system based RNG (one that takes a random number based on, say, eletrical current at the time of the function call?

My guess is you're right. The RNG in .NET is probably kind of crappy. Could you import a call from C+, or some other language that has a more robust PRNG?

Also, if you want to look at whether or not the RNG is behaving randomly, I would suggest 10,000 calls...just my opinion.

[unixknight]

Well I've got 2 paths to overall programming improvement.

The first is a much better random number generator that's high enough quality for encryption. I'm going to use that in my Dice class.

Second, instead of creating a new random object every time I roll the dice, I'm going to create it once and persist it across the various calls in the program, so that only the initial seed value is needed and everything after that will simply be next() calls on the object.

Basically my initial Dice class design was weak because I wrote it as a way to acclimate myself to VB.NET. (Previously I worked in C#.) I kinda wrote it on the side to get used to the syntax. At the time I wasn't too worried about the overall design.

[DigitalShadow]

Sorry, I wish I had seen this thread earlier since you probably already made a work around, but I don't often browse the advice forum. I believe the problem you are running in to is that the .NET random number generator is seeded with the current time and seeds when you create the Random object. It works best when you only create one instance of the Random object and reuse that.

For example, in this case the random number generated will most likely be the same each time:

for (int i =0; i < 100; i++)
{

Random r = new Random();
int random number = r.Next(0, 1000);

}

But in this case, the random number will be different:

Random r = new Random();
for (int i =0; i < 100; i++)
{

int random number = r.Next(0, 1000);

}

If you make the random object as a static field and only instantiate it once it should fix this. The .NET random number generate does not suck, it just has to be used properly

If you have any other .NET type questions let me know.

Edit: just noticed you already noticed this a couple posts up