Assign name of data frame to ggplot title in purrr loop - r

Question

I have two data sets from which I would like to generate histograms showing how the data overlap by name (A, B, C). I have written a custom function so I can use ggplot with map2.
I would like the graphs to be titled according to the name of each data set, so "A", "B", "C." Does anyone know of a way to do this?
# load packages
library(ggplot2)
library(dplyr)
library(purrr)
## load and format data 1
df1_raw <- data.frame(name = c("A", "B", "C", "A", "C", "B"),
start = c(1, 3, 4, 5, 2, 1),
end = c(6, 5, 7, 8, 6, 7))
df1 <- split(x = df1_raw, f = df1_raw$name) # split data by name
df1 <- lapply(df1, function(x) Map(seq.int, x$start, x$end)) # generate sequence intervals
df1 <- map(df1, unlist) # unlist sequences
df1 <- lapply(df1, data.frame) # convert to df
## load and format data 2
df2_raw <- data.frame(name = c("C", "B", "C", "A", "A", "B"),
start = c(5, 4, 3, 4, 4, 5),
end = c(7, 8, 7, 6, 9, 6))
df2 <- split(x = df2_raw, f = df2_raw$name) # split data by name
df2 <- lapply(df2, function(x) Map(seq.int, x$start, x$end)) # generate sequence intervals
df2 <- map(df2, unlist) # unlist sequences
df2 <- lapply(df2, data.frame) # convert to df
## write custom ggplot function and generate graphs
gplot <- function(data1, data2) {
ggplot() +
geom_histogram(data = data1, aes(x = X..i..), binwidth = 1, color = "grey", fill = "grey") +
geom_histogram(data = data2, aes(x = X..i..), binwidth = 1, fill = "pink", alpha = 0.7) +
labs(
title = ls(data1))
}
hist <- map2(df1, df2, gplot)
I also tried the following in the title field in my function:
deparse(substitute(data1))

Answer 1

Another similar option to what #GregorThomas mentioned in the comments, you could add a name variable to your data.frames and pull from that in your gplot() function. I've also shown how you might combine a few of your data manipulation steps:
# load packages
library(ggplot2)
library(dplyr)
library(purrr)
## load and format data 1
df1_raw <- data.frame(name = c("A", "B", "C", "A", "C", "B"),
start = c(1, 3, 4, 5, 2, 1),
end = c(6, 5, 7, 8, 6, 7))
df1 <- df1_raw %>%
split(.$name) %>% # split data by name
imap(function(x, x_name) {
data.frame(value = Map(seq.int, x$start, x$end) %>% unlist,
name = x_name)
})
## load and format data 2
df2_raw <- data.frame(name = c("C", "B", "C", "A", "A", "B"),
start = c(5, 4, 3, 4, 4, 5),
end = c(7, 8, 7, 6, 9, 6))
df2 <- df2_raw %>%
split(.$name) %>% # split data by name
imap(function(x, x_name) {
data.frame(value = Map(seq.int, x$start, x$end) %>% unlist,
name = x_name)
})
## change the title component of your previous function
gplot <- function(data1, data2) {
ggplot() +
geom_histogram(data = data1, aes(x = value), binwidth = 1, color = "grey", fill = "grey") +
geom_histogram(data = data2, aes(x = value), binwidth = 1, fill = "pink", alpha = 0.7) +
ggtitle(data1$name[1])
}
## plot it
map2(df1, df2, gplot)