# Category Archives: Floating Point

## Floating-Point Determinism

Is IEEE floating-point math deterministic? Will you always get the same results from the same inputs? The answer is an unequivocal “yes”. Unfortunately the answer is also an unequivocal “no”. I’m afraid you will need to clarify your question. My … Continue reading

Posted in Floating Point, Visual Studio | Tagged | 65 Comments

## Float Precision Revisited: Nine Digit Float Portability

Last year I pointed out that float variables can be converted to text and then back to the same binary value using printf(“%1.8e”). You can also use %.9g for more compact results. I also supplied a test program that used … Continue reading

Posted in Floating Point | | 17 Comments

## Top Eight Entertaining Blog Facts for 2012

The end of the year is a traditional time for lists and I thought I’d do a post just to summarize the most interesting or surprising things that I discovered while writing this blog during 2012.

Posted in Bugs, Floating Point, Performance, Programming | Tagged , , , | 1 Comment

## Game Developer Magazine Floating Point

This is for references, code examples, and discussion regarding the floating-point article in the October 2012 Game Developer Magazine.

Posted in Floating Point | | 3 Comments

## Doubles are not floats, so don’t compare them

I’ve seen a few online discussions linking to my Comparing Floating Point Numbers page for misguided reasons and I wanted to discuss those reasons to help people understand why throwing epsilons at the problem without understanding the situation is a … Continue reading

Posted in Floating Point, Programming | | 24 Comments

## Floating-Point Poetry

I gave a talk at iFest on Saturday that briefly covered some performance and precision issues taken from my series of floating-point blog posts. My talk was after Ed Fries, who did a brilliant talk on art and constraints, centered … Continue reading

Posted in Floating Point | Tagged , | 3 Comments

## That’s Not Normal–the Performance of Odd Floats

Denormals, NaNs, and infinities round out the set of standard floating-point values, and these important values can sometimes cause performance problems. The good news is, it’s getting better, and there are diagnostics you can use to watch for problems. In … Continue reading

| | 21 Comments

## Exceptional Floating Point

Floating-point math has an answer for everything, but sometimes that’s not what you want. Sometimes instead of getting an answer to the question sqrt(-1.0) (it’s NaN) it’s better to know that your software is asking imaginary questions. The IEEE standard … Continue reading

Posted in AltDevBlogADay, Floating Point, Programming | | 24 Comments

## Floating-point complexities

Binary floating-point math is complex and subtle. I’ve collected here a few of my favorite oddball facts about IEEE floating-point math, based on the articles so far in my floating-point series. The focus in this list is on float but … Continue reading

Posted in AltDevBlogADay, Floating Point, Programming | | 15 Comments

## Intermediate Floating-Point Precision

Riddle me this Batman: how much precision are these calculations evaluated at? If you answered ‘double’ and ‘float’ then you score one point for youthful idealism, but zero points for correctness. The correct answer, for zero-idealism points and forty two … Continue reading