Plot each y column against x and arrange in grids over multiple pages

multi_plot_loop.R

library(ggplot2)  # for plotting
library(gridExtra)  # for arranging plots

# Create example dataframe
df <- data.frame(x = letters[1:10]
                 , y1 = sample(1:100, 10)
                 , y2 = sample(1:100, 10)
                 , y3 = sample(1:100, 10)
                 , y4 = sample(1:100, 10)
                 , y5 = sample(1:100, 10)
                 )

# Loop through plots of each y col against x

ycols <- select(df, num_range("y", 1:5))  # columns to loop through

plot_list <- list()  # create empty list, which is filled by the loop

for (i in seq_along(1:length(y_cols))) {

  g <- ggplot(df, aes(x, y_cols[i])) + 
    geom_bar(stat = "identity") +
    labs(y = paste0("axis_", names(y_cols[i])))  # plot with custom y label
  
  name <- paste0("plot_", names(y_cols[i]))  # create name for the plot
  
  assign(name, g)  # give the name to the plot
  
  plot_list[[name]] <- g  # fill list with each ggplot object 
}

# Create 2x2 grid of the plots in plot_list
# New pages are created if there are more plots than nrow*ncol

gridExtra::marrangeGrob(plot_list, nrow = 2, ncol = 2)