I want to declare a one-dimension vector of length N called fd at the top of model block.

Error message was “PARSER EXPECTED: vector length declaration: integer expression in square brackets”, which was not reproduced in the code simulation here.

I have confirmed that N is an integer declared in the data block(first line). I did not see conflict in variable names. N has been used as vector length in previous declarations without any problem.

```
data{
int<lower=0> N; // number of observation
int<lower=0> S; // number of studies
int<lower=0> Gmax; // largest number of dose groups
int<lower=0,upper=Gmax> G[S]; // number of dose groups
vector[N] ymeanL; // ymean log
vector[N] ysdL; // ysd log
vector<lower=0>[N] Nsub; // number of subjects
row_vector[N] dose; // dose
}
transformed data{
row_vector[N] dosed; // transformed dose
dosed = ( dose - min(dose) ) / ( max(dose) - min(dose) );
}
parameters{
real<lower=0> sigma;
real<lower=0> c;
real<lower=1,upper=15> g;
vector<lower=0>[S] a;
vector<lower=0>[S] b;
real mu_a;
real<lower=0> sigma_a;
real mu_b;
real<lower=0> sigma_b;
}
model{
vector<lower=0>[N] fd;
int pos;
// Priors
sigma ~ uniform(0,10);
mu_a ~ uniform(-2,2);
sigma_a ~ uniform(0,2);
mu_b ~ uniform(-3,3);
sigma_b ~ uniform(0,2);
c ~ uniform(0,15);
g ~ uniform(1,15);
// Parameters
a ~ lognormal(mu_a,sigma_a);
b ~ lognormal(mu_b,sigma_b);
// Hill equation
pos = 1;
for(s in 1:S){
for(gg in pos:(pos+G[s]-1)){
fd[gg] = a[s] + ( b[s] * dosed[gg]^g ) / ( c^g + dosed[gg]^g );
}
pos = pos + G[s];
}
// Likelihood
target += -( Nsub/2*log(sigma^2) + ( Nsub*(ymeanL-log(fd))^2 + (Nsub-1)*ysdL^2 ) /
(2*sigma^2) );
}
```