library(urca) data(nporg) wg.n <- log(na.omit(nporg[, "wg.n"])) za.wg.n <- ur.za(wg.n, model = "intercept", lag = 7) ## plot(za.wg.n) wg.r <- log(na.omit(nporg[, "wg.r"])) za.wg.r <- ur.za(wg.r, model = "both", lag = 8) ## plot(za.wg.r)