在 R 中使用 ANOSIM 和 SIMPER 的不同结果
Different results using ANOSIM and SIMPER in R
我有 运行 ANOSIM 和 SIMPER 来分析两种处理的群落相似性。
当我 运行 ANOSIM 输出是：
ANOSIM 统计 R：-0.04465
显着性：0.749
意味着它们彼此相似？
但是我 运行 SIMPER 它说两种处理的成分相差 62%？
不确定如何解释两个测试的输出...为什么他们说的不同？
我查阅了文档。
- 它们彼此相似吗？是：
The divisor is chosen so that R will be in the interval -1 … +1, value
0 indicating completely random grouping.
62% 是否意味着组别不同？不，需要大于 70%。
该函数显示每对组最重要的物种。这些物种至少占组间差异的 70%。
还有这个注释：
The results of simper can be very difficult to interpret. The method
very badly confounds the mean between group differences and within
group variation, and seems to single out variable species instead of
distinctive species (Warton et al. 2012). Even if you make groups that
are copies of each other, the method will single out species with high
contribution, but these are not contributions to non-existing
between-group differences but to within-group variation in species
abundance.
我有 运行 ANOSIM 和 SIMPER 来分析两种处理的群落相似性。
当我 运行 ANOSIM 输出是：
ANOSIM 统计 R：-0.04465 显着性：0.749
意味着它们彼此相似？
但是我 运行 SIMPER 它说两种处理的成分相差 62%？
不确定如何解释两个测试的输出...为什么他们说的不同？
我查阅了文档。
- 它们彼此相似吗？是：
The divisor is chosen so that R will be in the interval -1 … +1, value 0 indicating completely random grouping.
62% 是否意味着组别不同？不，需要大于 70%。
该函数显示每对组最重要的物种。这些物种至少占组间差异的 70%。
还有这个注释：
The results of simper can be very difficult to interpret. The method very badly confounds the mean between group differences and within group variation, and seems to single out variable species instead of distinctive species (Warton et al. 2012). Even if you make groups that are copies of each other, the method will single out species with high contribution, but these are not contributions to non-existing between-group differences but to within-group variation in species abundance.