Apply a ggplot-function per group with dplyr and set title per group
I would like to create one separate plot per group in a data frame and include the group in the title.
With the iris dataset I can in base R and ggplot do this
plots1 <- lapply(split(iris, iris$Species),
function(x)
ggplot(x, aes(x=Petal.Width, y=Petal.Length)) +
geom_point() +
ggtitle(x$Species[1]))
Is there an equivalent using dplyr?
Here's an attempt using facets instead of title.
p <- ggplot(data=iris, aes(x=Petal.Width, y=Petal.Length)) + geom_point()
plots2 = iris %>% group_by(Species) %>% do(plots = p %+% . + facet_wrap(~Species))
where I use %+% to replace the dataset in p with the subset for each call.
or (working but complex) with ggtitle
plots3 = iris %>%
group_by(Species) %>%
do(
plots = ggplot(data=.) +
geom_point(aes(x=Petal.Width, y=Petal.Length)) +
ggtitle(. %>% select(Species) %>% mutate(Species=as.character(Species)) %>% head(1) %>% as.character()))
The problem is that I can't seem to set the title per group with ggtitle in a very simple way.
Thanks!
Use .$Species
to pull the species data into ggtitle
:
iris %>% group_by(Species) %>% do(plots=ggplot(data=.) +
aes(x=Petal.Width, y=Petal.Length) + geom_point() + ggtitle(unique(.$Species)))
library(dplyr, warn.conflicts = FALSE)
library(ggplot2)
plots3 <- iris %>%
group_by(Species) %>%
group_map(~ ggplot(.) + aes(x=Petal.Width, y=Petal.Length) + geom_point() + ggtitle(.y[[1]]))
length(plots3)
#> [1] 3
# for example, the second plot :
plots3[[2]]
Created on 2021-11-19 by the reprex package (v2.0.1)
This is another option using rowwise
:
plots2 = iris %>%
group_by(Species) %>%
do(plots = p %+% .) %>%
rowwise() %>%
do(x=.$plots + ggtitle(.$Species))