Hi, I was wondering if it’s possible to use Stan to simply sample from a density that I know the formula of up to proportionality?

Usually if I just want to sample from a density, then I might just write something like:

parameters {

y;

}

model {

y ~ some_pdf

}

But if I want to sample from a density proportional to e^(-x^4/8), how do I do this now?

Thanks in advance,

Ryan