`ud_init() ` takes `dat` as input, and `dat` can either from `mash_set_data()` or `X`. But `X` is not mentioned before using it. Same problem occurs in ``` U_scaled = list(indep = diag(ncol(X)), equal = matrix(1, ncol(X), ncol(X)) + 0.0001 * diag(ncol(X))) ``` See here: https://stephenslab.github.io/udr/reference/ud_init.html