Stan で相関係数を推定する - Qiita

library(rstan) N <- 1000 x <- rnorm(N, mean = 50, sd = 10) y <- 10 + 0.8 * x + rnorm(N, mean =0, sd = 7) data <- data.frame(x, y) stancode <- ' data{ int<lower=0> N; vector[2] y[N]; } parameters { vector[2] mu; real<lower=0> var_x; real<lower=0> var_y; real cov; } transformed parameters { matrix[2,2] sigma; sigma[1,1] <- var_x; sigma[2,1] <- cov; sigma[1,2] <- cov; sigma[2,2] <- var_y; } model{ fo