arbitrary number of plots for grid.arrange - r

Question

I'm trying to plot an arbitrary number of bar plots with rmarkdown separated by 2 columns. In my example there will be 20 total plots so I was hoping to get 10 plots in each column, however, I can't seem to get this to work with grid.arrange
plot.categoric = function(df, feature){
df = data.frame(x=df[,feature])
plot.feature = ggplot(df, aes(x=x, fill = x)) +
geom_bar() +
geom_text(aes(label=scales::percent(..count../1460)), stat='count', vjust=-.4) +
labs(x=feature, fill=feature) +
ggtitle(paste0(length(df$x))) +
theme_minimal()
return(plot.feature)
}
plist = list()
for (i in 1:20){
plist = c(plist, list(plot.categoric(train, cat_features[i])))
}
args.list = c(plist, list(ncol=2))
do.call("grid.arrange", args.list)
When I knit this to html I'm getting the following output:
I was hoping I would get something along the lines of:
but even with this the figure sizes are still funky, I've tried playing with heights and widths but still no luck. Apologies if this is a long question

Answer 1

If you have all the ggplot objects in a list then you can easily build the two column graphic via gridExtra::grid.arrange. Here is a simple example that will put eight graphics into a 4x2 matrix.
library(ggplot2)
library(gridExtra)
# Build a set of plots
plots <-
lapply(unique(diamonds$clarity),
function(cl) {
ggplot(subset(diamonds, clarity %in% cl)) +
aes(x = carat, y = price, color = color) +
geom_point()
})
length(plots)
# [1] 8
grid.arrange(grobs = plots, ncol = 2)