/**********************************************************************
 * survival analysis  
 **********************************************************************/

data {
    int<lower=0> p; 
    
    int<lower=0> n_event;
    vector[n_event] time_event;
    matrix[n_event, p] x_event;

    int<lower=0> n_censor;
    vector[n_censor] time_censor;
    matrix[n_censor, p] x_censor; 
}
parameters {
    real mu; 
    vector[p] beta; 
    real<lower=0> sigma;
}
model {
    vector[n_event] z_event;
    z_event = mu + x_event * beta; 
    time_event ~ weibull(1/sigma, exp(z_event)); 

    vector[n_censor] z_censor;
    z_censor = mu + x_censor * beta; 
    target += weibull_lccdf(time_censor | 1/sigma, exp(z_censor)); 
}

/**********************************************************************
 * THE END 
 **********************************************************************/