> df
     A        B
1 1.138289 1.918876
2 1.621082 2.432379
3 1.295929 2.241403
4 1.325516 1.845258

mvrnorm(n = 4, mu = center, Sigma = as.matrix(cov(df)), empirical = F)
        A        B
[1,] 1.364986 2.235192
[2,] 1.116274 1.828175
[3,] 1.438028 2.256231
[4,] 1.586585 1.956803