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			| Re: OT: Can someone explain this? [message #183334 is a reply to message #183221] | 
			Fri, 23 December 2005 12:30    | 
		 
		
			
				
				
				
					
						  
						=HT=T-Bird
						 Messages: 712 Registered: June 2005 
						
	Karma: 0
 
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					Colonel  | 
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		Mathematics assumes that numbers have infinite precision.  However, that's not possible with computers that use floating-point arithmetic, so you get round-off that gives you really tiny numbers instead of 0.  Example of the WRONG way to do things (in C++): 
 
float f1 = 2.0 - 1.0;
float f2 = 1.0;
if (f1 == f2)
std::cout << "this might not happen";
else
std::cout << "oops...floating point round-off";
  
(I still haven't figured out how to insert tabs in forum posts   ) 
and the RIGHT way: 
float f1 = 2.0 - 1.0;
float f2 = 1.0;
if (std::fabs (f1 - f2) < std::numeric_limits <float>::epsilion ())
std::cout << "this works";
  
 
I hope this helps
		
		
  HTT-Bird (IRC) 
HTTBird (WOL) 
Proud HazTeam Lieutenant. 
BlackIntel Coder & Moderator. 
 
If you have trouble running BIATCH on your FDS, have some questions about a BIATCH message or log entry, or think that BIATCH spit out a false positive, PLEASE contact the BlackIntel coding team and avoid wasting the time of others.
		
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			| Re: OT: Can someone explain this? [message #183349 is a reply to message #183339] | 
			Fri, 23 December 2005 12:57    | 
		 
		
			
				
				
				
					
						  
						=HT=T-Bird
						 Messages: 712 Registered: June 2005 
						
	Karma: 0
 
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					Colonel  | 
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		| icedog90 wrote on Fri, 23 December 2005 13:45 |   Why don't you use "using namespace std;" so that you don't have to put std:: in front of everything from the iostream library?
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It's bad form.  Dragging in namespaces wholesale leads to name conflicts m8...p.s. it's the STL, not the iostream library
		
		
  HTT-Bird (IRC) 
HTTBird (WOL) 
Proud HazTeam Lieutenant. 
BlackIntel Coder & Moderator. 
 
If you have trouble running BIATCH on your FDS, have some questions about a BIATCH message or log entry, or think that BIATCH spit out a false positive, PLEASE contact the BlackIntel coding team and avoid wasting the time of others.
		
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