[s:15] 弱弱的问一个问题,比较confused的。
是关于用anova做两个回归比较的。对于一批数据:
<br />
y genotype1 genotype2 genotype3 genotype4 genotype5 genotype6 richness<br />
0.723180717 1 0 0 0 0 0 1<br />
0.586778142 1 0 0 0 0 0 1<br />
0.529518697 1 0 0 0 0 0 1<br />
0.583116337 1 0 0 0 0 0 1<br />
0.341646543 0 1 0 0 0 0 1<br />
0.536072361 0 1 0 0 0 0 1<br />
0.351945993 0 1 0 0 0 0 1<br />
0.506105539 0 1 0 0 0 0 1<br />
0.544939085 0 0 1 0 0 0 1<br />
0.407603593 0 0 1 0 0 0 1<br />
0.506329912 0 0 1 0 0 0 1<br />
0.741982902 0 0 1 0 0 0 1<br />
0.463839265 0 0 0 1 0 0 1<br />
0.663213919 0 0 0 1 0 0 1<br />
1.483604733 0 0 0 1 0 0 1<br />
0.814709899 0 0 0 1 0 0 1<br />
0.614014969 0 0 0 0 1 0 1<br />
0.528801797 0 0 0 0 1 0 1<br />
0.318580474 0 0 0 0 1 0 1<br />
0.859761906 0 0 0 0 1 0 1<br />
0.38543611 0 0 0 0 0 1 1<br />
0.403032238 0 0 0 0 0 1 1<br />
0.677303673 0 0 0 0 0 1 1<br />
0.348691052 0 0 0 0 0 1 1<br />
0.292563789 0 1 0 0 1 1 3<br />
0.429824076 0 1 0 0 1 1 3<br />
0.652613592 1 0 0 1 0 1 3<br />
0.480955349 1 0 0 1 0 1 3<br />
0.440973581 1 0 0 0 1 1 3<br />
0.399052881 1 0 0 0 1 1 3<br />
0.641560974 0 1 1 1 0 0 3<br />
0.40382416 0 1 1 1 0 0 3<br />
0.53297655 1 1 1 0 0 0 3<br />
0.493328994 1 1 1 0 0 0 3<br />
0.376233281 0 0 1 1 1 0 3<br />
0.935145865 0 0 1 1 1 0 3<br />
0.610169431 1 1 1 1 1 1 6<br />
0.561760343 1 1 1 1 1 1 6<br />
0.468095174 1 1 1 1 1 1 6<br />
0.664972679 1 1 1 1 1 1 6<br />
0.460805827 1 1 1 1 1 1 6<br />
0.53915795 1 1 1 1 1 1 6<br />
<br />
<br />
用以下程序执行:<br />
<br />
abc = lm(Y.biomass ~ ., data=data)<br />
ab = lm(Y.biomass ~ genotype.1 +genotype.2 +genotype.3 +genotype.4 +genotype.5 +genotype.6, data=data)<br />
bc = lm(Y.biomass ~ richness, data=data)<br />
<br />
anova(abc, ab)执行结果是:<br />
<br />
<br />
Analysis of Variance Table<br />
<br />
Model 1: y ~ genotype1 + genotype2 + genotype3 + genotype4 + genotype5 + <br />
genotype6 + richness<br />
Model 2: y ~ genotype1 + genotype2 + genotype3 + genotype4 + genotype5 + <br />
genotype6<br />
Res.Df RSS Df Sum of Sq F Pr(>F)<br />
1 35 1.2632 <br />
2 35 1.2632 0 0.0000 <br />
两个自由度都是35?按照我上面这个模型的话,永远都没有自由度分配给以上
两个Model的比较结果,不知道我理解的对不对,谢谢大家!