16个处理(4*2*2)的析因组合被重复三次,并在条裂区块中布置。处理包括8个样地准备(4×2)作为整个小区处理和两个水平的除草(除草/不除草)随机应用于子样地。在Genstat中运行分析,得到以下结果:
Variate: result
Source of variation d.f. s.s. m.s. v.r. F pr.
Rep stratum 2 35.735 17.868
Rep.Burning stratum
Burning 1 0.003 0.003 0.00 0.972
Residual 2 3.933 1.966 1.53
Rep.Site_prep stratum
Site_prep 3 7.981 2.660 0.45 0.727
Residual 6 35.477 5.913 4.61
Rep.Burning.Site_prep stratum
Burning.Site_prep 3 2.395 0.798 0.62 0.626
Residual 6 7.691 1.282 0.60
Rep.Burning.Site_prep.*Units* stratum
Weeding 1 13.113 13.113 6.13 0.025
Burning.Weeding 1 0.486 0.486 0.23 0.640
Site_prep.Weeding 3 17.703 5.901 2.76 0.076
Burning.Site_prep.Weed.3 3.425 1.142 0.53 0.666
Residual 16 34.248 2.141
Total 47 162.190 我想在R中重复这些结果。我使用了base::aov函数和lmerTest::lmer函数。我设法使用函数result ~ Burning * Weeding * Site.prep + Error(Rep/Burning*Site.prep)获得了aov的正确结果。对于lmer,我使用了函数result ~ Burning*Site.prep*Weeding+(1|Rep/(Burning:Site.prep)),只给出了部分正确的结果。燃烧、Site.prep和Burning:Site.prep的SS值和F值与Genstat结果的偏差(尽管不是太大),但除草和除草交互作用产生的SS和F值与Genstat输出的SS和F值相同。我想知道我应该如何指定lmer模型来重现Genstat和aov结果。数据和代码如下:
x <- structure(list(
Rep = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L,
2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("1", "2", "3"
), class = "factor"),Burning = structure(c(1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L,
2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 1L), .Label = c("Burn",
"No-burn"), class = "factor"), Site.prep = structure(c(4L, 4L,4L, 4L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 1L, 1L, 1L, 1L, 2L, 2L,
2L, 2L, 1L, 1L, 1L, 1L, 4L, 4L, 4L, 4L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 1L, 1L, 1L, 1L, 4L, 4L, 4L, 4L),
.Label = c("Chop_Pit", "Chop_Rip", "Pit", "Rip"), class = "factor"), Weeding = structure(c(1L,
2L, 1L, 2L, 1L, 2L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 2L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 1L, 2L, 2L, 1L, 1L,
2L, 1L, 2L, 2L, 1L, 1L, 2L, 2L, 1L, 1L, 2L, 1L, 2L, 1L, 2L),
.Label = c("Weedfree", "Weedy"), class = "factor"),
Dbh14 = c(27.4, 28.4083333333333, 27.7066666666667, 27.3461538461538, 28.6, 28.3333333333333, 27.0909090909091,
27.8076923076923, 27.1833333333333, 27.5461538461538, 24.3076923076923,
29.3461538461538, 27.4, 25.1, 26.61, 28.0461538461538, 27.71,
25.2533333333333, 25.3833333333333, 24.2307692307692, 24.2533333333333,
24.95, 24.34375, 26.9909090909091, 24.775, 25.9076923076923,
25.1666666666667, 25.9933333333333, 27.0466666666667, 30.5625,
27.36, 25.2636363636364, 29.6846153846154, 27.7, 28.3071428571429,
29.4857142857143, 27.025, 30.1, 31.2454545454545, 24.2888888888889,
28.4875, 29.23, 30, 28.5, 29.3615384615385, 27.45, 28.8153846153846,
29.1866666666667)), .Names = c("Rep", "Burning", "Site.prep",
"Weeding", "result"), class = "data.frame", row.names = c(NA, -48L))
model1 <- aov(result ~ Burning* Weeding*Site.prep+ Error(Rep/Burning*Site.prep), data=x)
summary(model1)
model2 <- lmer(result ~ Burning*Site.prep*Weeding+(1|Rep/(Burning:Site.prep)),data=x)
anova(model2)发布于 2017-07-31 04:04:47
应用@cuttlefish44 44提到的site中的三向分裂图阶乘方差分析示例,可以得出:
library(lme4)
library(nlme)
m1 <- aov(result ~ Weeding*Burning*Site.prep + Error(Rep/Burning*Site.prep), data=x)
m2 <- lmer(result ~ Weeding*Burning*Site.prep + (1|Rep) + (1|Burning:Rep) +
(1|Site.prep:Rep), data=x)
m3 <- anova(lme(result ~ Weeding*Burning*Site.prep,
random=list(Rep=pdBlocked(list(~1, pdIdent(~Burning-1), pdIdent(~Site.prep-1)))),
method="ML", data=x))
summary(m1)
anova(m2)
m3除了Site.prep之外,结果都是匹配的。此外,lmer()和lme()之间的结果非常相似(对于Site.prep也是如此)。我不确定这是否是建模方法差异的结果:多级方法既考虑了内部影响,也考虑了影响之间的影响。
https://stackoverflow.com/questions/39434385
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