```
if (FALSE) {
showClass("stanfit")
ecode <- '
parameters {
real y[2];
}
model {
y ~ exponential(1);
}
'
fit <- stan(model_code = ecode, iter = 10, chains = 1)
fit2 <- stan(fit = fit)
print(fit2)
plot(fit2)
traceplot(fit2)
ainfo <- get_adaptation_info(fit2)
cat(ainfo[[1]])
seed <- get_seed(fit2)
sp <- get_sampler_params(fit2)
sp2 <- get_sampler_params(fit2, inc_warmup = FALSE)
head(sp[[1]])
lp <- log_prob(fit, c(1, 2))
grad <- grad_log_prob(fit, c(1, 2))
lp2 <- attr(grad, "log_prob") # should be the same as "lp"
# get the number of parameters on the unconstrained space
n <- get_num_upars(fit)
# parameters on the positive real line (constrained space)
y1 <- list(y = rep(1, 2))
uy <- unconstrain_pars(fit, y1)
## uy should be c(0, 0) since here the log transformation is used
y1star <- constrain_pars(fit, uy)
print(y1)
print(y1star) # y1start should equal to y1
}
# Create a stanfit object from reading CSV files of samples (saved in rstan
# package) generated by funtion stan for demonstration purpose from model as follows.
#
excode <- '
transformed data {
real y[20];
y[1] <- 0.5796; y[2] <- 0.2276; y[3] <- -0.2959;
y[4] <- -0.3742; y[5] <- 0.3885; y[6] <- -2.1585;
y[7] <- 0.7111; y[8] <- 1.4424; y[9] <- 2.5430;
y[10] <- 0.3746; y[11] <- 0.4773; y[12] <- 0.1803;
y[13] <- 0.5215; y[14] <- -1.6044; y[15] <- -0.6703;
y[16] <- 0.9459; y[17] <- -0.382; y[18] <- 0.7619;
y[19] <- 0.1006; y[20] <- -1.7461;
}
parameters {
real mu;
real sigma;
vector[2] z[3];
real alpha;
}
model {
y ~ normal(mu, sigma);
for (i in 1:3)
z[i] ~ normal(0, 1);
alpha ~ exponential(2);
}
'
# exfit <- stan(model_code = excode, save_dso = FALSE, iter = 200,
# sample_file = "rstan_doc_ex.csv")
#
exfit <- read_stan_csv(dir(system.file('misc', package = 'rstan'),
pattern='rstan_doc_ex_[[:digit:]].csv',
full.names = TRUE))
print(exfit)
if (FALSE) {
plot(exfit)
}
adaptinfo <- get_adaptation_info(exfit)
inits <- get_inits(exfit) # empty
inits <- get_inits(exfit, iter = 101)
seed <- get_seed(exfit)
sp <- get_sampler_params(exfit)
ml <- As.mcmc.list(exfit)
cat(get_stancode(exfit))
```

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