Floating-Point Comparisons: Pitfalls and Practical Solutions
2025-05-15
This article delves into the complexities of comparing floating-point numbers. The author highlights the unreliability of simple equality checks due to inherent precision limitations and accumulated rounding errors. Two comparison methods are detailed: relative error (epsilon) and ULP (Units in the Last Place), along with their strengths and weaknesses. The article emphasizes the failure of relative error comparisons near zero, proposing a solution combining absolute error. A compelling example using `sin(π)` demonstrates catastrophic cancellation and how floating-point representation errors can improve π's accuracy.
Development
precision