Hi, I am trying to run the following stan model with the given data. But it gave me the following error.

trying deprecated constructor; please alert package maintainer

Error in new_CppObject_xp(fields$.module, fields$.pointer, …)

Anyone can help? Thank you very much!

stan.m="

data {

int<lower=0> N[1];

vector<lower=0>[N[1]] dose;

real<lower=0> dr;

int DLT[N[1]];

int total[N[1]];

vector[2] mu;

cov_matrix[2] Sigma;

}

parameters {

vector[2] log_ab;

}

transformed parameters {

real log_a = log_ab[1];

real log_b = log_ab[2];

real<lower=0> b = exp(log_b);

}

model {

vector[N[1]] prob;

// Prior

log_ab~multi_normal(mu, Sigma);

//likelihood

for(i in 1:N[1]){

prob[i]=exp(log_a + b*log(dose[i]/dr))/(1+exp(log_a + b*log(dose[i]/dr)));

DLT[i] ~ binomial(total[i],prob[i]);

}

}

"

stan_data <- list(

dose = c(800),

total = c(7),

DLT = c(1),

N = 1,

dr = dr,

```
mu = mu,
Sigma = Sigma,
Rho = rho
```

)

fit = stan(model_code=stan.m, data=stan_data, iter=1000, chains=4,thin=2)