I have a list of dataframes and I would like to print them all in a .RMarkdown document with 2 per page. However, I have not been able to find a source for doing this. Is it possible to do this via a for loop?
What I would like to achieve is something with the following idea:
listOfDataframes <- list(df1, df2, df3, ..., dfn)
for(i in 1:){
plot <- ggplot(listOfDataframes[i], aes(x = aData, y = bData)) + geom_point(color = "steelblue", shape = 19)
#if two plots have been ploted break to a new page.
}
Is this possible to achieve with ggplot in rmarkdown? I need to print out a PDF document.
If you just need to output plots with two per page, then I would use gridExtra as was suggested above. You could do something like this if you were to put your ggplot objects into a list.
library(ggplot2)
library(shinipsum) # Just used to create random ggplot objects.
library(purrr)
library(gridExtra)
# Create some random ggplot objects.
ggplot_objects <- list(random_ggplot("line"), random_ggplot("line"))
# Create a list of names for the plots.
ggplot_objects_names <- c("This is Graph 1", "This is Graph 2")
# Use map2 to pass the ggplot objects and the list of names to the the plot titles, so that you can change them.
ggplot_objects_new <-
purrr::map2(
.x = ggplot_objects,
.y = ggplot_objects_names,
.f = function(x, y) {
x + ggtitle(y)
}
)
# Arrange each ggplot object to be 2 per page. Use marrangeGrob so that you can save two ggplot objects per page.
ggplot_arranged <-
gridExtra::marrangeGrob(ggplot_objects_new, nrow = 2, ncol = 1)
# Save as one pdf. Use scale here in order for the multi-plots to fit on each page.
ggsave("ggplot_arranged.pdf",
ggplot_arranged, scale = 1.5)
If you have a list of dataframes that you are wanting to create ggplots for, then you can use purrr::map to do that. You could do something like this:
purrr::map(df_list, function(x) {
ggplot(data = x, aes(x = aData, y = bData)) +
geom_point(color = "steelblue", shape = 19)
})