Cannot replicate a matrix in paramter block

Hi There,

I am trying to devleop a multiple bayesian change model according to the stan manual:

However in my stan model, as I am trying to define a matrix for log_p = rep_matrix(-log(N),N); the stan gaves me error that “No Match for available argument signature for rep_matrix”. However I checked both manual and the tutrial which they used this function. Could you help me why I give this error?

``````transformed parameters {
matrix[N,N] log_p;
real mu;
real sigma;
log_p = rep_matrix(-log(N),N);
for (tau in 1:N)
for(tau2 in 1:N){
for (i in 1:N) {
mu = i < tau ? (mu1 * x[i] + gamma1) :(i < tau2 ?(mu2 * x[i] + gamma2):(mu3 * x[i] + gamma3));
sigma = i < tau ? sigma1 : (i < tau2 ? sigma2:sigma3);
log_p[tau,tau2] = log_p[tau,tau2] + normal_lpdf(y[i] | mu, sigma);
}
}
}
``````

If you’re using `rep_matrix()` to fill a matrix with a single scalar value (i.e., `-log(N)`), you need to provide both the number of rows and the number of columns that you want to create:

``````log_p = rep_matrix(-log(N), N, N);
``````
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Thank you very much andrew. It is now working

Dear Andrew, so in the stan manual this should be correcet. beacuse it seems that they forgot to correctly use rep_matrix(***, N, N) as you kindly mentions here

Which section of the manual are you referring to? Because if you pass a vector or row-vector to `rep_matrix()`, then only one size is needed

I read this section which i immagine it is not a vector

Yep that’s a typo, thanks for catching!

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