Hello,
I have the strange beeing :
float f1 = 108.88F;
float f2 = 111.11F;
float f3 = f1 - f2;
double d1 = 108.88;
double d2 = 111.11;
double d3 = d1 - d2;
f3 contains -2.23000336
d3 contains -2.2300000000000 04
instead of -2.23.
Am i missing something ?
Regards,
Cybertof.
4  1690 
Hi cybertor,
This is normal behavious of binary based floating point variables.
They are only rounded to the value you want.
You might try using decimal variables instead.
--
Miha Markic - RightHand .NET consulting & development
miha at rthand com
"cybertof" <cy************ ****@gmx.net> wrote in message
news:MP******** *************** @msnews.microso ft.com... Hello,
I have the strange beeing :
float f1 = 108.88F;
float f2 = 111.11F;
float f3 = f1 - f2;
double d1 = 108.88;
double d2 = 111.11;
double d3 = d1 - d2;
f3 contains -2.23000336
d3 contains -2.2300000000000 04
instead of -2.23.
Am i missing something ?
Regards,
Cybertof.
Hi Miha !
How do you explain ?
Does it mean that with single & double, you always get calculation
errors ?
When can you use binary based floating point variables if you cannot
make correct calculations with them ?
Regards,
Cybertof.
In article <O1************ **@TK2MSFTNGP11 .phx.gbl>, "Miha Markic" <miha
at rthand com> says... Hi cybertor,
This is normal behavious of binary based floating point variables.
They are only rounded to the value you want.
You might try using decimal variables instead.
This document may help explain it: http://portal.acm.org/citation.cfm?i...TOKEN=87893990
--
Eric Gunnerson
Visit the C# product team at http://www.csharp.net
Eric's blog is at http://blogs.gotdotnet.com/ericgu/
This posting is provided "AS IS" with no warranties, and confers no rights.
"cybertof" <cy************ ****@gmx.net> wrote in message
news:MP******** *************** *@msnews.micros oft.com... Hi Miha !
How do you explain ?
Does it mean that with single & double, you always get calculation
errors ?
When can you use binary based floating point variables if you cannot
make correct calculations with them ?
Regards,
Cybertof.
In article <O1************ **@TK2MSFTNGP11 .phx.gbl>, "Miha Markic" <miha
at rthand com> says... Hi cybertor,
This is normal behavious of binary based floating point variables.
They are only rounded to the value you want.
You might try using decimal variables instead.
cybertof <cy************ ****@gmx.net> wrote: How do you explain ?
Does it mean that with single & double, you always get calculation
errors ?
Often, yes - but not always.
When can you use binary based floating point variables if you cannot
make correct calculations with them ?
In fact, the calculations may well be performing without any error, but
with the initial values not being what you think they were.
See http://www.pobox.com/~skeet/csharp/floatingpoint.html for more
information.
--
Jon Skeet - <sk***@pobox.co m> http://www.pobox.com/~skeet
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