Not intended to be called directly by the user
.plot_mixed( x, i = 1:ncol(x$mmkin), degparms_optim, degparms_pop, residuals, obs_vars = names(x$mkinmod$map), standardized = TRUE, xlab = "Time", xlim = range(x$data$time), resplot = c("predicted", "time"), ymax = "auto", maxabs = "auto", ncol.legend = ifelse(length(i) <= 3, length(i) + 1, ifelse(length(i) <= 8, 3, 4)), nrow.legend = ceiling((length(i) + 1)/ncol.legend), rel.height.legend = 0.03 + 0.08 * nrow.legend, rel.height.bottom = 1.1, pch_ds = 1:length(i), col_ds = pch_ds + 1, lty_ds = col_ds, frame = TRUE, ... )