如何在C＃中使用step平滑Random？

Question

How to generate random value from 5 to 10 with step 0.4?

I tried:

var numberOfSteps = 0.4;
var _step = (maximum - minimum) / numberOfSteps;
var difference = maximum - minimum;
var stepsToDifference = Math.Round(difference / _step);
return Convert.ToString(minimum + _step * stepsToDifference);

Answer 1

How about something like this:

Random rand = new Random();
int intPart = 0;
int multiplesOfPointFour = 0;
bool doAgain = true;
double finalValue = 0.0;
while (doAgain)
{
    intPart = rand.Next(5, 8);
    multiplesOfPointFour = rand.Next(0, 6);
    finalValue = intPart + (multiplesOfPointFour * 0.4);
    Console.WriteLine("Value is: " + finalValue.ToString());
    Console.Write("Press any key to go again...");
    Console.ReadKey();                
}

So we pick an integer between 5 and 10 and then add 0.4 a random number of times between 0 and 12 to that integer, because 5.0 / 0.4 = 12.5

Answer 2

Do you mean you want the number to be 5, 5.4, 5.8, ... 10? As 5 and 10 are 5 apart and not evenly divisible by .4, you will have to either stop at 9.8 or at 10.2 or stop at 10 with a short step at the last.

But here is how you can get a random number that is a member of that set (will be any number from 5 to 9.8 on the even .4 step).

Random rand = new Random();
float randomInSet = ((float)rand.Next(0,12)*.4)+5;

Please let me know if this is not what you had in mind.

Answer 3

Was trying to generate a random Hue to create really different colors, so here it is:

    //***************************************************************************
    public static partial class RndExtensions
    //***************************************************************************
    {
    //-------------------------------------------------------------
    public static double NextDouble(this Random rnd, double from, double to, double step)
    //-------------------------------------------------------------
    {
        var delta = to - from;
        var nbOfSteps = (int)(delta / step);
        var randomStep = rnd.Next(0, nbOfSteps);
        return step*randomStep + from; 
    }
    //-------------------------------------------------------------
    public static double Next(this Random rnd, int from, int to, int step)
    //-------------------------------------------------------------
    {
        var delta = to - from;
        var nbOfSteps = (int)(delta / step);
        var randomStep = rnd.Next(0, nbOfSteps);
        return step * randomStep + from;
    }
    }

Used as

Random rnd = new Random();
var randomHue = rnd.NextDouble(0, 359, 25);