解释方差分析 table 的 R 显着性代码?

Interpeting R significance codes for ANOVA table?

测试数据框:

> foo
      x     y     z
1 0.191 0.324 0.620
2 0.229 0.302 0.648
3 0.191 0.351 0.626
4 0.229 0.324 0.630
5 0.152 0.374 0.656
6 0.191 0.295 0.609
7 0.229 0.267 0.665
8 0.152 0.353 0.657
9 0.152 0.355 0.655

两个线性模型:

model1 <- lm(z~polym(x,y,degree = 1),data=foo)
model2 <- lm(z~polym(x,y,degree = 2),data=foo)

两个模型的方差分析 returns:

> anova(model1,model2)
Analysis of Variance Table

Model 1: z ~ polym(x, y, degree = 1)
Model 2: z ~ polym(x, y, degree = 2)
  Res.Df      RSS Df Sum of Sq    F Pr(>F)  
1      6 0.002988                           
2      3 0.000169  3   0.00282 16.6  0.023 *
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

为什么单身*? 0.05 > 0.023 > 0.01,那么它不应该打印一个 . 符号吗?

没什么问题。

0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

表示:

annotation          p-value          significance level
   ***            [0, 0.001]                0.001
    **         (0.001, 0.01]                0.01
     *          (0.01, 0.05]                0.05
     .           (0.05, 0.1]                0.1
                    (0.1, 1]                1

0.023在(0.01, 0.05]以内,所以应该用*注释。