I'm trying to produce a visualisation using {echarts4r} that involves plotting points with labels displayed on the chart itself, where the labels are unrelated to the position of the points. This sounds like it should be simple, but so far I haven't found any viable method of doing this and I'm beginning to wonder if it's even possible.
Here is a minimal example. I will use {ggplot2} to demonstrate what I'd (roughly) like to reproduce:
data <- data.frame(
date_eaten = as.Date(c("2020-01-01", "2020-01-02", "2020-01-03")),
tastiness = c(5, 7, 10),
fruit = c("apple", "orange", "mango")
)
data
#> date_eaten tastiness fruit
#> 1 2020-01-01 5 apple
#> 2 2020-01-02 7 orange
#> 3 2020-01-03 10 mango
library(ggplot2)
ggplot(data, aes(x = date_eaten, y = tastiness, label = fruit)) +
geom_point() +
geom_text(nudge_y = 0.2)
e_labels()
This method is visually exactly what I want, however, it seems that there is no option to specify which columns to take the labels from.
library(echarts4r)
data %>%
e_chart(date_eaten) %>%
e_scatter(tastiness, symbol_size = 10) %>%
e_labels()
e_mark_point()
This option allows for more customisation, however this is not really a viable solution as it is very clunky and doesn't strictly 'link back' to the original data:
data %>%
e_chart(date_eaten) %>%
e_scatter(tastiness, symbol_size = 10) %>%
e_mark_point(data = list(
xAxis = as.Date("2020-01-01"),
yAxis = 5,
value = "apple"
)) %>%
e_mark_point(data = list(
xAxis = as.Date("2020-01-02"),
yAxis = 7,
value = "orange"
)) %>%
e_mark_point(data = list(
xAxis = as.Date("2020-01-03"),
yAxis = 10,
value = "mango"
))
I think this is the solution. Currently I'm not sure exactly how it works as documentation is a bit limited, but it seems to work:
data %>%
e_chart(date_eaten) %>%
e_scatter(tastiness, symbol_size = 10, bind = fruit) %>%
e_labels(formatter = htmlwidgets::JS("
function(params) {
return(params.name)
}
"))