∫ 误差函数 erf / erfcError Function Calculator
erf(x) = 2/√π ∫₀ˣ e^(-t²) dt，用高精度级数/连分式计算，并给出 erfc = 1 - erf。本地处理。erf(x) = 2/√π ∫₀ˣ e^(-t²) dt via high-precision series / continued fraction, plus erfc = 1 - erf. Processed locally.
使用说明与常见问题How-to & FAQ
「误差函数 erf / erfc」是什么？What is the Error Function Calculator tool?
erf(x) = 2/√π ∫₀ˣ e^(-t²) dt，用高精度级数/连分式计算，并给出 erfc = 1 - erf。本地处理。erf(x) = 2/√π ∫₀ˣ e^(-t²) dt via high-precision series / continued fraction, plus erfc = 1 - erf. Processed locally.
如何使用「误差函数 erf / erfc」？How do I use the Error Function Calculator tool?
填写 x，即可得到误差函数 erf(x) 和互补误差函数 erfc(x) = 1 − erf(x)。结果会随输入实时更新。Enter x to get the error function erf(x) and the complementary erfc(x) = 1 − erf(x). The result updates as you type.
与正态分布？Normal distribution?
Φ(z) = (1 + erf(z/√2)) / 2。Φ(z) = (1 + erf(z/√2)) / 2.
能举个计算实例吗？Can you show a worked example?
例如在「误差函数 erf / erfc」中填 x = 0.5，结果区显示：erf(x)：0.520499877813；erfc(x)：0.479500122187For example, entering x = 0.5 in the Error Function Calculator gives: erf(x): 0.520499877813; erfc(x): 0.479500122187
哪些输入会被检查？Which inputs are validated?
「误差函数 erf / erfc」会检查这些输入——「x」：必须填写；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Error Function Calculator checks its inputs — "x": required; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.
有哪些选项可以调整？What options can I adjust?
「误差函数 erf / erfc」的设置：「x」默认 0.5。每次生成结果都按当前设置处理。Settings in the Error Function Calculator — "x" default 0.5. The result always uses the current settings.
计算精度如何？How precise are the results?
「误差函数 erf / erfc」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Error Function Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「误差函数 erf / erfc」免费吗？需要注册吗？Is the Error Function Calculator free? Do I need an account?
「误差函数 erf / erfc」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Error Function Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.