The problem is that I have to multiply by 100 before rounding, so the double must no be off by more than 0.005. For example, if 4.56 is actually stored as 4.5610, the number multiplied by 100 will be 456.100 which gets to 456.600 when adding 0.5 which rounds up to 457.
I feel like my brain is about to explode... -----Original Message----- From: Discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] Behalf Of Terry Griffin Sent: Monday, August 25, 2008 1:27 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] Converting doubles into integers without rounding errors The problem with going from a double to an int is that the final digit can be cut off because the double is inexact. But the double will be close. All you need to do is add 0.5 to the value before doing the conversion to an int. The "extra" 0.5 will make a value like 4.999999999 get converted to 5 instead of 4. Unless your original numbers are off by a large amount (close to 0.5) this won't introdcue any error. int intVal; double dblVal; intVal = (int)(dbleVal * 100 + 0.5); Terry Griffin Sr. Software Engineer Carl Zeiss SMT Inc. ALIS Business Unit 1 Corporation Way Peabody, MA 01960 USA [EMAIL PROTECTED] (978) 826-1569 Daniel Barla-Szabo <[EMAIL PROTECTED]> Sent by: "Discussion of advanced .NET topics." <ADVANCED-DOTNET@DISCUSS.DEVELOP.COM> 08/25/2008 01:10 PM Please respond to "Discussion of advanced .NET topics." <ADVANCED-DOTNET@DISCUSS.DEVELOP.COM> To ADVANCED-DOTNET@DISCUSS.DEVELOP.COM cc Subject Re: [ADVANCED-DOTNET] Converting doubles into integers without rounding errors Personally, I've never used it before, but I see in framework 2.0 there is the option of: (int) Double.Truncate(objMyObject.Amount * 100); HTH -----Original Message----- From: Discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Eddie Lascu Sent: 25 August 2008 06:28 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: [ADVANCED-DOTNET] Converting doubles into integers without rounding errors Hello everyone, I have some objects that contain an amount field that is declared as double. Since it contains amounts, it always has only two decimal digits that are significant. During the process I need to convert that double into an integer by removing the decimal point. For example, $78.59 should be converted to integer 7859 and $101.53 to 10153. in my code I have uint nIntAmount = (uint)(objMyObject.Amount * 100); The problem I am facing is that sometimes, very rarely, there is a rounding error that is introduced and the integer obtained is off by a cent (plus or minus). For example, this is a line that was traced in my log file: "Updating the batch with $137.89 as the amount in the transaction. This amount was converted to 13788." Can either of you suggest a different way to convert the amounts in integers without this nagging rounding error? Any help will be appreciated, Eddie =================================== This list is hosted by DevelopMentorR http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com ---------------------------------------- This message is intended for a particular addressee only and may contain business or company secrets. If you have received this email in error, please contact the sender and delete the message immediately. Any use of this email, including saving, publishing, copying, replication or forwarding of the message or the contents is not permitted. =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
