Combine multiple plots from a list-column onto a page by group for multi-page PDF-CodePudding

I've created two dataframes as a result of running two different models on the same data. Each dataframe contains a list-column with one plot per row. I would eventually like to print all plots to a PDF, but pair the plots with the same grouping variable on a single page of a multi-page PDF. For example, in the simplified example below, I would like the plot from model_figs1 where cyl == "6" to be on the same page to the left of the plot from model_figs2' where cyl == "6"`.

Here is some example data:

library(tidyverse)    
    
# I am sure you could combine model_figs1 & model_figs2 into one process/code chunk,
# but this is an overly simplified example and should be kept separate:

model_figs1 <-
  mtcars %>% 
  group_by(cyl) %>% 
  nest() %>% 
  mutate(plot = map(data, ~ggplot(data = .x, 
                                   aes(x = hp, y = mpg))  
                       geom_point()  
                       geom_smooth(method = "lm")  
                       labs(subtitle = cyl)))

model_figs2 <-
  mtcars %>% 
  group_by(cyl) %>% 
  nest() %>% 
  mutate(plot = map(data, ~ggplot(data = .x, 
                                   aes(x = hp, y = mpg))  
                       geom_point()  
                       geom_smooth(method = "loess")  
                       labs(subtitle = cyl)))

# Bind the dfs together
model_figs <-
  bind_rows(model_figs1, model_figs2, .id = "id")

How do I pair plots with the same grouping variable value onto a single PDF page while printing all plots to a multi-page PDF at once?

CodePudding user response：

If there are only two plots per group, then we can use ggsave with marrangeGrob after arrangeing by the group column

library(gridExtra)
library(dplyr)
model_figs <- model_figs %>%
              arrange(cyl)
ggsave(filename = file.path(getwd(), "Downloads/newplots.pdf"), 
    plot = marrangeGrob(model_figs$plot, ncol = 2, nrow = 1))