statsmodels错误消息:“ValueError:v在p>=.9时必须大于1”

似乎你必须提供比每组一次观察更多的数据,才能让测试起作用。

最简单的例子:

from statsmodels.stats.multicomp import pairwise_tukeyhsd,MultiComparison

data=[1,2,3]
groups=['a','b','c']

print("1st try:")
try:
        print(pairwise_tukeyhsd(data,groups, alpha=0.05))
except ValueError as ve:
        print("whoops!", ve)


data.append(2)
groups.append('a')
print("2nd try:")
try:
        print( pairwise_tukeyhsd(data, groups, alpha=0.05))
except ValueError as ve:
        print("whoops!", ve)

输出:

1st try:
/home/user/.local/lib/python3.7/site-packages/numpy/core/fromnumeric.py:3367: RuntimeWarning: Degrees of freedom <= 0 for slice
  **kwargs)
/home/user/.local/lib/python3.7/site-packages/numpy/core/_methods.py:132: RuntimeWarning: invalid value encountered in double_scalars
  ret = ret.dtype.type(ret / rcount)
whoops! v must be > 1 when p >= .9
2nd try:
Multiple Comparison of Means - Tukey HSD, FWER=0.05 
====================================================
group1 group2 meandiff p-adj  lower    upper  reject
----------------------------------------------------
     a      b      0.5   0.1  -16.045  17.045  False
     a      c      1.5   0.1  -15.045  18.045  False
     b      c      1.0   0.1 -18.1046 20.1046  False
----------------------------------------------------