📊 P值计算器P-Value Calculator
由 z 值、t 值（自由度）、卡方值或 F 值计算单尾/双尾 P 值，并与显著性水平 α 比较。P-value from a z-score, t-score (with df), chi-square or F statistic, one- or two-tailed, compared with a significance level α.
使用说明与常见问题How-to & FAQ
「P值计算器」是什么？What is the P-Value Calculator tool?
由 z 值、t 值（自由度）、卡方值或 F 值计算单尾/双尾 P 值，并与显著性水平 α 比较。P-value from a z-score, t-score (with df), chi-square or F statistic, one- or two-tailed, compared with a significance level α.
如何使用「P值计算器」？How do I use the P-Value Calculator tool?
在「P值计算器」中，填写「分布」、「检验统计量」、「自由度 df（t、χ²；F 为分子 df）」、「分母自由度(F)」、「检验类型」等参数，结果会随输入实时计算并显示在下方。In the P-Value Calculator: Fill in "Distribution", "Test statistic", "Degrees of freedom (t, χ²; numerator for F)", "Denominator df (F)", "Tails"; results are recalculated instantly as you type.
用的是什么算法？How is it computed?
正态分布用互补误差函数，t 分布和 F 分布用正则化不完全 Beta 函数，卡方用正则化不完全 Gamma 函数（连分式展开），精度约 10 位有效数字。The normal uses the complementary error function, t and F use the regularized incomplete beta function, and chi-square the regularized incomplete gamma function (continued fractions), accurate to about 10 significant digits.
单尾还是双尾？One- or two-tailed?
检验“是否不同”用双尾；检验“是否更大/更小”的方向性假设用右尾/左尾。双尾 χ²、F 检验较少见，这里取两侧较小尾概率的 2 倍。Use two-tailed for "is it different" and right/left-tailed for directional hypotheses. Two-tailed χ² and F tests are unusual; here they use twice the smaller tail.
计算精度如何？How precise are the results?
「P值计算器」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 P-Value Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「P值计算器」免费吗？需要注册吗？Is the P-Value Calculator free? Do I need an account?
「P值计算器」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 P-Value 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.