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Writing a function to round to "arbitrary" precision in C#

I wish create a function (or use one if it already exists) that can round to any precision.

I have calculation that returns a value, often with a lot of decimals.
Say I have

5557.8554154707894045251247690

And sometimes I wanna round it to the nearest whole number. => 5558
Sometimes to nearest .1 => 5557.9
Or to .00001 => 5557.85542
And so on.

kiruba_karan_d

Hi

//Round (Number, NumDigitsAfterDecimal)
System.Math.Round(22.3433, ); //22.3

TimCottee

Hello letharion,

Math.Round(Number,Precision);

At its most basic, there are a number of options available with this that also allow you control over how midpoint rounding is carried out etc.

Regards,

TimCottee

kiruba_karan_d

Hi

Math.Round(5557.8, 1, MidpointRounding.AwayFromZero) = 5557.9

Math.Round(5557.8, 1, MidpointRounding.ToEven) = 5557.8

TimCottee

kiruba_karan_d,

Actually not quite, 5557.8 will always be rounded to 5557.8 with 1 decimal place.

5557.85 would be rounded to 5557.9 and 5557.8 respectively using those methods.

TimCottee

letharion

ASKER

I realise I wasn't really clear. Your solutions are great, but I might also want to round to the nearest .25 or the nearest 1/32 (0.03125)

That's where things get complicated. I should've taken such examples in my original post.

TimCottee

letharion,

That is a little trickier but then you have to apply the old methods. Multiply by your factor, apply rounding and then divide by your factor to get the result.

TimCottee

letharion

ASKER

TimCottee: I'm sorry, but I don't understand. The way I read your post:

Desired result 5557.8554 rounded to .25 => 5557.75
5557.8554 * 25 = 138946.385 =>
138946 / 25 = 5557.84

ASKER CERTIFIED SOLUTION

TimCottee

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letharion

ASKER

Thank you very much. Works wonders :)

Writing a function to round to &quot;arbitrary&quot; precision in C#

Writing a function to round to "arbitrary" precision in C#