Round to interval: code snippet + problem

December 9th, 2009, 04:01 PM

Hi

In my strategy I need to round a number to multiple of an interval and have a choice of rounding up, down, and to the nearest mulitple of interval. I've found following code snippet that should do the job exactly as I need it:

Code

                            
public static decimal RoundToInterval(decimal value, decimal interval, IntervalRounding rounding)
{
   // Guard against the divide by zero exception
   if (interval == 0)
      return decimal.MinValue;
 
   decimal result = value / interval;
 
   switch (rounding)
   {
          case IntervalRounding.Nearest:
             return (decimal.Round(result, 0, MidpointRounding.AwayFromZero) * interval);
          case IntervalRounding.Up:
             return (decimal.Ceiling(result) * interval);
          case IntervalRounding.Down:
             return (decimal.Floor(result) * interval);
          default:
             return decimal.MinValue;
   }
 
}

Public enum required would be:

Code

                            
public enum IntervalRounding {Nearest = 0, Up = 1, Down = 2}

Now the problem is I can't get it to work. And when I use:

Code

                            
RoundToInterval(3.83, 2, Down);

Expected behavior would be number 2 but...

I receive an error:
"The name 'Down' does not exist in the current context"

Am I missing something?

December 9th, 2009, 06:00 PM

Try with:

Code

                            
RoundToInterval(3.83, 2, IntervalRounding.Down);

December 9th, 2009, 06:18 PM

Thanks Sam,

That was what I was missing.
Now it works for integers (RoundToInterval(3,2,IntervalRounding.Down) but stops when I use the example above (3.83, 2) - it says: Argument 1: cannot convert from double to decimal.

Do you know how to correct this or eventually know any other way of achieving what I need?

Thanks again

December 9th, 2009, 08:02 PM

Well, I have received my C# humility lesson. My programming experience is very limited and I have no experience with strong typing languages at all...

Anyway for my example to work I had to use following code:

Code

                            
RoundToInterval(Convert.ToDecimal(3.83), Convert.ToDecimal(2), IntervalRounding.Down)

Round to interval: code snippet + problem

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Round to interval: code snippet + problem