■

> sqr.obs<-function(x){
n<-sum(x)
pob<-x/n
print(pob)
}
#関数の定義
> data
     [,1] [,2]
[1,]    5    7
[2,]   13   12
> sqr.obs(data)->data.obs
          [,1]      [,2]
[1,] 0.1351351 0.1891892
[2,] 0.3513514 0.3243243

> ES.w2(data.obs)->data.w
> data.w
[1] 0.09678053
#Cohenのeffect sizeを算出。

> pwr.chisq.test(w=data.w,df=1,N=37000)　#Nを1000倍

     Chi squared power calculation 

              w = 0.09678053
              N = 37000
             df = 1
      sig.level = 0.05
          power = 1

 NOTE: N is the number of observations 


> pwr.chisq.test(w=data.w,df=1,N=370)　#Nを10倍

     Chi squared power calculation 

              w = 0.09678053
              N = 370
             df = 1
      sig.level = 0.05
          power = 0.4608922

 NOTE: N is the number of observations 

検出力が上がってます。