I want to display a latex equation in a shiny application. I saw an example where mathjax is used to display latex equations. But for some reason the equation generated from equatiomatic package does not display correctly. Following is a reproducible example:
library(shiny)
library(tidyverse)
library(broom)
library(equatiomatic)
## Loading Dataset
data(mpg)
mpg2 <- mpg %>%
select(where(is.numeric))
## User Interface
ui <- fluidPage(
withMathJax(),
sidebarPanel(
selectInput(inputId = "xcol",
label = "Select an explanatory variable",
choices = colnames(mpg2),
selected = "cty"),
selectInput(inputId = "ycol",
label = "Select a response variable",
choices = colnames(mpg2),
selected = "hwy")
),
mainPanel(
plotOutput('plot'),
br(),
uiOutput('eq'),
br(),
tableOutput('table1'),
br(),
tableOutput('table2')
)
)
## Server
server <- function(input, output, session) {
data <- reactive({
mpg2 %>%
select(col1 = input$xcol, col2 = input$ycol)
})
output$plot <- renderPlot({
ggplot(data()) +
geom_point(aes(col1, col2)) +
labs(x = input$xcol, y = input$ycol)
})
output$table1 <- renderTable({
m1 <- lm(reformulate(input$xcol, input$ycol), data = mpg2)
broom::tidy(m1)
})
output$table2 <- renderTable({
m1 <- lm(reformulate(input$xcol, input$ycol), data = mpg2)
broom::glance(m1)[, 1:2]
})
output$eq <- renderUI({
m1 <- lm(reformulate(input$xcol, input$ycol), data = mpg2)
withMathJax(helpText(extract_eq(m1)))
})
}
shinyApp(ui, server)
Interesting, it seems like shiny is expecting the equation as raw character string. Hence it is missing a \ for all Latex operators.
One (not very pretty) way to fix it would be:
output$eq <- renderUI({
m1 <- lm(reformulate(input$xcol, input$ycol), data = mpg2)
withMathJax(helpText(
paste0("$$", as.character(extract_eq(m1)), "$$")
)
)
})
However I am not too familiar with the package so not sure if this is intended or a bug... Have you considered opening an issue at the equatiomatic GitHub?