3 ms·
Pure cargo-culting. There are circumstances in which it’s perfectly appropriate to compare floating-point data for equality. There are also circumstances in w
by stephencanon 13y ago
Pure cargo-culting. There are circumstances in which it’s perfectly appropriate to compare floating-point data for equality. There are also circumstances in which a comparison with some tolerance is more appropriate. Understand what situation you’re in, and understand the tools that you’re using.
- TeMPOraL 13y agoComparing floats for equality is equivalent to comparing them with tolerance that you don't control. I don't see a good reason to risk like that.
- stephencanon 13y agoNo, it's not equivalent to that at all. Why would you think such a thing?
- nitrogen 13y agoRead the wikipedia entry on IEEE754-1985 (it has better diagrams than the main 754 entry): http://en.wikipedia.org/wiki/IEEE_754-1985#Representation_of_numbers http://en.wikipedia.org/wiki/IEEE_754-1985#Representation_of... Knowing is better than fearing.
- millstone 13y agoComparing floats for equality is equivalent to a comparison with zero tolerance, not an uncontrolled tolerance. Consider storing a timestamp as a number of seconds since the epoch. We might use == to check if the timestamp has changed.