卡方检验的二项式负概率分布问题

时间:2019-03-05 00:07:32

标签: r distribution probability-density chi-squared probability-distribution

我想创建一个测试二项式负概率分布的循环,但是不起作用。在我的示例中:

创建包含2个变量的人工数据集-Feature和Resp(响应变量)

#Package
library(MASS)

Features<-sort(rep(1:3,30))
Resp1<-rnbinom(60,0.75,0.10) ##60 Negative binomial values
Resp2<-rpois(30,10)## 30 Poisson values
Resp<-c(Resp1,Resp2)
d<-as.data.frame(cbind(Features,Resp))

应用基于卡方的二项式阴性检验

uniq <- unique(unlist(d$Features))
res<-NULL
for (i in 1:length(uniq)){
    data_1 <- subset(d, Features == uniq[i])
    k <- fitdistr(data_1$Resp,"negative binomial") #Extraction of probability parameters (size and mu)
    par <- k$estimate
    size <- par[1]#k parameter
    mu <- par[2]#Mean
    N <- length(data_1$Resp)
    est <-N*dnbinom(data_1$Resp,size=size,mu=mu)  ## Estimation of values 
    fecdf <- ecdf(data_1$Resp) ###ecdf- Cumulative empirical distribution
    knotsX <- knots(fecdf)
    emp <- fecdf(c(knotsX,Inf))  # Empirical distribution
    testChi<-chisq.test(table(emp),table(est),correct=TRUE) #Chi square test empirical vs estimated values
    result<-ifelse(testChi$p.value>0.05,"Binomial Negative","Other distribution") 
    res<-rbind(res,c(uniq[i],result))
    colnames(res)<-c("Features","Distribution")
} 
res

     Features Distribution        
[1,] "1"      "Binomial Negative" 
[2,] "2"      "Other distribution"
[3,] "3"      "Binomial Negative"

不起作用,因为我的前60个数字具有二项式负数(特征1和2),而后30个数字(特征3)具有泊松分布(我在创建人工数据集时对此值进行了模拟)。我的股票在哪里出问题? 预先感谢!

0 个答案:

没有答案