httpstan_stan_model_compile_hmc_sampling_posterior_draws.py

1import asyncio
2import httpstan
3
4program_code = """
5data {
6    int<lower=0> N;
7    array[N] int<lower=0,upper=1> y;
8}
9parameters {
10    real<lower=0,upper=1> theta;
11}
12model {
13    theta ~ beta(1,1);
14    for (n in 1:N)
15        y[n] ~ bernoulli(theta);
16}
17"""
18data = {"N": 10, "y": [0, 1, 0, 0, 0, 0, 0, 0, 0, 1]}
19
20async def main():
21    # build the model
22    model_name = await httpstan.models.build(program_code)
23
24    # start sampling
25    payload = {
26        "function": "stan::services::sample::hmc_nuts_diag_e_adapt",
27        "data": data,
28    }
29    operation = await httpstan.services.create_operation(model_name, payload)
30    
31    # wait for sampling to finish
32    operation = await httpstan.operations.wait(operation["name"])
33    
34    # get the draws
35    fit_name = operation["result"]["name"]
36    draws_bytes = await httpstan.fits.get_fit(fit_name)
37    
38    # print the size of the result
39    print(f"Sampling finished. Received {len(draws_bytes)} bytes of draws.")
40
41if __name__ == "__main__":
42    asyncio.run(main())