java - ROUND_HALF_EVEN 为什么以及如何在重复应用于一系列计算时最小化累积误差？

Question

我听说 ROUND_HALF_EVEN 是财务数据计算的首选舍入模式。我很想知道这种舍入模式为什么以及如何减少 javadoc BigDecimal 1.4.2 中所述的累积误差。谢谢，院长

Answer 1

来自 Wikipedia :

Despite the custom of rounding the number 4.5 up to 5, in fact 4.5 is no nearer to 5 than it is to 4 (it is 0.5 away from both). When dealing with large sets of scientific or statistical data, where trends are important, traditional rounding on average biases the data upwards slightly. Over a large set of data, or when many subsequent rounding operations are performed as in digital signal processing, the round-to-even rule tends to reduce the total rounding error, with (on average) an equal portion of numbers rounding up as rounding down. This generally reduces upwards skewing of the result.