library(tidyverse)
library(magrittr)
library(purrr)
library(forcats)

base <- expand.grid(chem = c("Th", "Ta", "Nb", "La", "Ce", "P", "Zr", "Hf", "Sm", "Ti", "Y", "Yb", "Lu"),
            id=1:7)


grouping <- data.frame(id=1:7,
                       trend=rep(c("WNW", "NE"),
                                 times=c(2,5)))

dat <- inner_join(base, grouping)

dat %<>%
  split( list(.$chem, .$trend)) %>%
  map(~mutate(.x, mean = rlnorm(n=1))) %>%
  map(~mutate(.x,
              y = rlnorm(n=nrow(.x),
                         meanlog = .$mean,
                         sdlog = 0.1))) %>%
  bind_rows %>%
  mutate(chem = fct_inorder(chem)) %>%
  arrange(chem, id)

ggplot(data=dat, aes(x=chem, y=y)) +
  geom_line(aes(group=id, lty=trend)) +
  scale_y_log10() +
  theme_bw()  +
  annotation_logticks(sides="lr")