How to do simple arithmetic in CmdStan

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1

I know it seems like overkill, but I wanted to know if it is possible to make simple functions in cmdStan with no sampling. Say for example say I wanted to make a function that squared the a value.

The code below compiles, but when I try to run it I just get the standard help information asking for the data file. And the sampler I want to use. How can I just run a simple function like this?


functions{
  real foo(data real x) {
  return x^2;
  }
}

transformed data {
  real x=2;
  real a;
  a = foo(x);
  print(a);
}
2

Nah, there is no way to expose functions to the command line line this in cmdstan sorry.

expose_stan_functions does this in Rstan. There’ve been talks about doing various things like this for cmdstan but no big plans or anything.

3

Though if you just want to print, the simplest way of doing it is selecting sample and algorithm=fixed_param and setting the number of samples to 1.

If you want the result in the CSV output you could

functions{
   real foo(data real x) {
      return x^2;
   }
}
generated quantities {
       real a = foo(2);
}

and again setting the fixed_param algorithm with 1 sample.

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