用于在JAGS中定义分布的if/else语句 [英] if/else statement for defining a distribution in JAGS

问题描述

在JAGS中，我想为参数w [i]定义泊松分布，如果另一个参数e [i]大于0，该参数也会被截断(大于或等于2).

In JAGS I'd like to define a Poisson distribution for parameter w[i] which is also truncated (greater than or equal to 2) if another parameter, e[i], is greater than 0.

基本上我希望它代表:

w [i]〜ifelse(e [i]> 0，dpois(mu)T(2，)，dpois(mu))

w[i] ~ ifelse( e[i] > 0, dpois(mu) T(2,) , dpois(mu) )

我尝试使用step函数来调整为响应其他人的帖子而提供的代码，该帖子要求类似的内容:

I've tried using the step function by adapting the code that was given in response to someone else's post which was requesting something similar: Choosing Different Distributions based on if - else condition in WinBugs/JAGS

但这似乎不起作用吗?

谢谢

推荐答案

也许是这样?

pois1 ~ dpois(mu) T(2,)
pois2 ~ dpois(mu)
for(i in 1:N){
indicator1[i] <- ifelse(e[i] > 0, 1, 0)
indicator2[i] <- ifelse(e[i] <= 0, 1, 0)
w[i] <- (pois1 * indicator1[i]) + (pois2 * indicator2[i])
}

当e[i]大于1时，w[i]从pois1中获取值.如果不是，则w[i]从pois2获取值.

When e[i] is greater than 1 w[i] takes the value from pois1. If it is not w[i] takes the value from pois2.

或者，您可以仅定义一个指标变量，并像这样进行.

Or, you could define only one indicator variable and do it like this.

pois1 ~ dpois(mu) T(2,)
pois2 ~ dpois(mu)
for(i in 1:N){
indicator[i] <- ifelse(e[i] > 0, 1, 0)
w[i] <- (pois1 * indicator[i]) + (pois2 * (1 - indicator[i]))
}

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