data { int N; int K1; int y1[N]; matrix[N,K1] x1; } parameters { real alpha1; real lambda ; vector [K1] tau_tilde_sqr; vector[K1] beta1_tilde; } transformed parameters { //vector[K1] tau = tau_tilde /lambda; real lambda2 =1/lambda; vector[K1] tau = (tau_tilde_sqr)*lambda2; vector[K1] beta1= beta1_tilde .* sqrt(tau) ; } model { beta1_tilde ~ normal(0, 1); lambda ~ cauchy(0, 1); tau_tilde_sqr ~ inv_gamma (0.5 , 0.5 ); alpha1 ~ normal(0, 1); y1 ~ bernoulli_logit_glm(x1, alpha1, beta1); }