Rounding floating-point numbers to 4 decimal points

Posted by Himadri on Stack Overflow See other posts from Stack Overflow or by Himadri
Published on 2010-05-14T05:55:34Z Indexed on 2010/05/14 6:04 UTC
Read the original article Hit count: 296

Filed under:

rounding

|

floating-point

I have two decimal numbers. I want those number to be same upto 4 decimal points without rounding. If numbers are different I want 2nd number to be replaced by 1st. What if condition should I write?

Eg,
1.

num1 = 0.94618976  
num2 = 0.94620239

If we round these numbers upto 4 decimal then we get 0.9462 same number, but I don't want to round these numbers.

2.

num1 = 0.94620239  
num2 = 0.94639125

The one way I found is take absolute difference of both numbers say diff and then check the value. My problem is of checking the range of diff.

Thank You.

© Stack Overflow or respective owner

Related posts about rounding

Why do you need float/double?

as seen on Programmers - Search for 'Programmers'
I was watching http://www.joelonsoftware.com/items/2011/06/27.html and laughed at Jon Skeet joke about 0.3 not being 0.3. I personally never had problems with floats/decimals/doubles but then I remember I learned 6502 very early and never needed floats in most of my programs. The only time I used… >>> More
Round-twice error in .NET's Double.ToString method

as seen on Stack Overflow - Search for 'Stack Overflow'
Mathematically, consider for this question the rational number 8725724278030350 / 2**48 where ** in the denominator denotes exponentiation, i.e. the denominator is 2 to the 48th power. (The fraction is not in lowest terms, reducible by 2.) This number is exactly representable as a System.Double… >>> More
T-SQL - Date rounding and normalization

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi: I have a stored procedure that rounds a column with dates in (yyyy:mm:dd hh:mM:ss) to the nearest 10 minute handle (yyyy:mm:dd hh:mM) 20100303 09:46:3000 ------ 20100303 09:50 but i want to chage it to round it off to the nearest 15 minute handle: 20100303 09:46:3000 ------20100303 09:45 here… >>> More
C# Double - ToString formatting with two decimal places and no rounding

as seen on Stack Overflow - Search for 'Stack Overflow'
How can i format a Double to String in c# so as to have only two decimal digits? If I use String.Format("{0:0.00}%", myDoubleValue) the number is rounded, and i want a simple truncate without rounding. Also, I want the conversion to String to be culture sensitive. >>> More
Hard-coded 8191 10485 values in JavaScript rounding function

as seen on Stack Overflow - Search for 'Stack Overflow'
I've seen the following (bizarre) Javascript rounding function in some legacy code. After googling for it I can see that it crops up in a number of places online. However I can't work out why the hard-coded values 8191 and 10485 are present. Does anyone know if there's any sensible reason why these… >>> More

Related posts about floating-point

Comparing floating point values

as seen on Stack Overflow - Search for 'Stack Overflow'
I just read a statement about the floating point value comparison Floating point values shall not be compared using either the == or != operators. Most floating point values have no exact binary representation and have a limited precision. If so what is the best method for comparing two floating… >>> More
understanding floating point variables

as seen on Stack Overflow - Search for 'Stack Overflow'
There is some problem, i can't understand anyway. look at this code please <script type="text/javascript"> function math(x) { var y; y = x*10; alert(y); } </script> <input type="button" onclick="math(0.011)"> What must be alerted after i click on button? i think 0.11… >>> More
floating point hex octal binary

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am working on a calculator that allows you to perform calculations past the decimal point in octal, hexadecimal, binary, and of course decimal. I am having trouble though finding a way to convert floating point decimal numbers to floating point hexadecimal, octal, binary and vice versa. The… >>> More
What is a Bias Value of Floating Point Numbers?

as seen on Stack Overflow - Search for 'Stack Overflow'
In learning how floating point numbers are represented in computers I have come across the term "bias value" that I do not quite understand. The bias value in floating point numbers has to do with the negative and positiveness of the exponent part of a floating point number. The bias value of a… >>> More
Why are floating point values so prolific?

as seen on Stack Overflow - Search for 'Stack Overflow'
So, title says it all. Why are floating point values so prolific in computer programming. Due to problems like rounding errors, and not being able to even accurately represent numbers such as 0.1, I really can't see how they got as far as they did. I understand that the computation is faster… >>> More