How can I change the number of breaks of x axis for each graph individually for each facet in a facet_grid in R?

Question

How can I change the number of breaks of x axis for each graph individually for each facet in a facet_grid? I would like to modify the x-axis separately for each facet. I have tried with scale_x_continuos(breaks =..., n.breaks = ...) but I can't. I also removed the theme_set(theme_paleo(8)) with theme_replace and tried with theme(axis.x.text =, axis.ticks =, etc etc) but without positive result, anyone who can help me please.

This is the example for stratigraphic diagrams in this link: https://cran.r-project.org/web/packages/tidypaleo/vignettes/strat_diagrams.html

Code:

library(tidyverse)
library(tidypaleo)
theme_set(theme_paleo(8))

data("alta_lake_geochem")

alta_lake_geochem

alta_plot <- ggplot(alta_lake_geochem, aes(x = value, y = depth)) +
  geom_lineh() +
  geom_point() +
  scale_y_reverse() +
  facet_geochem_gridh(vars(param)) +
  labs(x = NULL, y = "Depth (cm)")

alta_plot

alta_plot

Answer 1

One option is the ggh4x package which via facetted_pos_scales allows to set the scales individually for each facet. In the code below I use facetted_pos_scales to set the breaks for the first and the third facet, while for all other facets the default is used ( NULL ).

Note 1: facetted_pos_scales requires to the free the x scale via scales="free_x" .

Note 2: To make facetted_pos_scales work with scale_y_reverse I had to move scale_y_reverse inside facetted_pos_scales too.

library(tidyverse)
library(tidypaleo)
library(ggh4x)

theme_set(theme_paleo(8))

data("alta_lake_geochem")

ggplot(alta_lake_geochem, aes(x = value, y = depth)) +
  geom_lineh() +
  geom_point() +
  facet_geochem_gridh(vars(param), scales = "free_x") +
  labs(x = NULL, y = "Depth (cm)") +
  facetted_pos_scales(
    x = list(
      scale_x_continuous(breaks = 1:8),
      NULL,
      scale_x_continuous(n.breaks = 10),
      NULL
    ),
    y = list(
      scale_y_reverse()
    )
  )