# 그룹별 평균 차이에 대해서 가능한 그룹 쌍에 대해 쌍체 t 검정하기
>>> pairwise.t.test(count, spray, p.adjust="bonferroni")
Pairwise comparisons using t tests with pooled SD

data: count and spray

   A         B         C        D        E
B  1         -         -        -        -
C  1.1e-09   1.3e-10   -        -        -
D  1.5e-06   1.8e-07   1        -        -
E  4.1e-08   4.9e-09   1        1        -
F  1         1         4.2e-12  6.1e-09  1.6e-10

P value adjustment method: bonferroni

# 투키 HSD 검정하기
>>> TukeyHSD(aov.out)
Tukey multiple comparisons of means
   95% family-wise confidence level

Fit: aov(formula = count ~ spray, data = InsectSprays)

$spray
            diff          lwr         upr       p adj
B-A    0.8333333    -3.866075    5.532742   0.9951810
C-A  -12.4166667   -17.116075   -7.717258   0.0000000
D-A   -9.5833333   -14.282742   -4.883925   0.0000014
E-A  -11.0000000   -15.699409   -6.300591   0.0000000
F-A    2.1666667    -2.532742    6.866075   0.7542147
C-B  -13.2500000   -17.949409   -8.550591   0.0000000
D-B  -10.4166667   -15.116075   -5.717258   0.0000002
E-B  -11.8333333   -16.532742   -7.133925   0.0000000
F-B    1.3333333    -3.366075    6.032742   0.9603075
D-C    2.8333333    -1.866075    7.532742   0.4920707
E-C    1.4166667    -3.282742    6.116075   0.9488669
F-C   14.5833333     9.883925   19.282742   0.0000000
E-D   -1.4166667    -6.116075    3.282742   0.9488669
F-D   11.7500000     7.050591   16.449409   0.0000000
F-E   13.1666667     8.467258   17.866075   0.0000000