How to get mouse over labels in a shiny ggplot2 polar plot? - r

Question

I'm struggeling with mouse over labels for my ggplot 2 polar plot in shiny.
Simple version of my code (without mouse over labels):
library(dplyr)
library(shiny)
library(ggplot2)
# Define UI for application that plots features of iris
ui <- fluidPage(
br(),
# Sidebar layout
sidebarLayout(
# Inputs
sidebarPanel(
),
# Outputs
mainPanel(
plotOutput(outputId = "radarplot"),
br()
)
)
)
# Define server function required to create the radarplot
server <- function(input, output) {
# Create radarplot with iris dataset
output$radarplot <- renderPlot ({
iris %>%
ggplot(.) + geom_histogram(aes(y = Petal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 1 ) +
geom_histogram(aes(y = Sepal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 0.3) +
coord_polar()
})
}
# Create a Shiny app object
shinyApp(ui = ui, server = server)
I made a version using plotly, trying to add mouse over labels. But then I don't get a radar plot.
library(dplyr)
library(shiny)
library(ggplot2)
library(plotly)
# Define UI for application that plots features of iris
ui <- fluidPage(
br(),
# Sidebar layout
sidebarLayout(
# Inputs
sidebarPanel(
),
# Outputs
mainPanel(
plotlyOutput(outputId = "radarplot"),
br()
)
)
)
# Define server function required to create the radarplot
server <- function(input, output) {
# Create radarplot with iris dataset
output$radarplot <- renderPlotly ({
iris %>%
ggplot(.) + geom_histogram(aes(y = Petal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 1 ) +
geom_histogram(aes(y = Sepal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 0.3) +
coord_polar()
})
}
# Create a Shiny app object
shinyApp(ui = ui, server = server)
Ideally I want the mouse over label to give output about Petal.Width, Sepal.Width and Species when hovering over a particular Species 'wing'.
Any suggestions how to get these mouse over labels?

Answer 1

Here is an example of this using the ggiraph package.
First the tooltip needs to be created.
library(tidyverse)
iris_group_means <-
iris %>%
group_by(Species) %>%
summarise_all(mean) %>%
mutate(tooltip = sprintf("Sepal Length: %1.2f\nSepal Width: %1.2f\nPetal Length: %1.2f\nPetal Width: %1.2f",
Sepal.Length, Sepal.Width, Petal.Length, Petal.Width)) %>%
select(Species, tooltip)
Then this tooltip just needs to be provided as an aesthetic, and instead of geom_histogram, use the ggiraph::geom_histogram_interactive function.
my_gg <-
iris %>%
ggplot() +
geom_histogram(aes(y = Petal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 1 ) +
ggiraph::geom_histogram_interactive(aes(y = Sepal.Width, x = Species, fill = Species, tooltip = tooltip),
binwidth= 1,
stat= 'identity',
alpha = 0.3) +
coord_polar()
ggiraph::ggiraph(code = print(my_gg))
This can then be used in Shiny. A few other steps are involved and there is a separate ggiraph::renderggiraph function to use. Details are on the ggiraph site
Here is the final Shiny code. I don't use shiny much so this can probably be improved upon, but it worked for me.
# Define UI for application that plots features of iris
ui <- fluidPage(
br(),
# Sidebar layout
sidebarLayout(
# Inputs
sidebarPanel(
),
# Outputs
mainPanel(
ggiraph::ggiraphOutput(outputId = "radarplot"),
br()
)
)
)
# Define server function required to create the radarplot
server <- function(input, output) {
# Create radarplot with iris dataset
output$radarplot <- ggiraph::renderggiraph ({
iris_group_means <-
iris %>%
group_by(Species) %>%
summarise_all(mean) %>%
mutate(tooltip = sprintf("Sepal Length: %1.2f\nSepal Width: %1.2f\nPetal Length: %1.2f\nPetal Width: %1.2f",
Sepal.Length, Sepal.Width, Petal.Length, Petal.Width)) %>%
select(Species, tooltip)
iris <-
left_join(iris, iris_group_means, by="Species")
my_gg <-
iris %>%
ggplot() +
geom_histogram(aes(y = Petal.Width, x = Species, fill = Species),
binwidth= 1,
stat= 'identity',
alpha = 1 ) +
ggiraph::geom_histogram_interactive(aes(y = Sepal.Width, x = Species, fill = Species, tooltip = tooltip),
binwidth= 1,
stat= 'identity',
alpha = 0.3) +
coord_polar()
ggiraph::ggiraph(code = print(my_gg))
})
}
# Create a Shiny app object
shinyApp(ui = ui, server = server)