r - mathjax 在闪亮的应用程序中不起作用

Question

我一直在尝试将一些简单的 mathjax 表达式添加到我闪亮的应用程序中，但一直失败。然后我查看了一些在线示例，即使这些示例也无法在我的计算机上运行。例如，我尝试运行此问题的代码，但未显示 mathjax 表达式。

library(shiny)
shinyApp(ui = shinyUI(fluidPage(sliderInput("order", withMathJax("Order, \\(k\\)"), min = 3, max = 7, value = 4, step = 1), 
                                sliderInput("iknots", "iKnots", min = 0, max = 10, value = 5, step = 1),
                                uiOutput("lastSlider"))), 

         server = shinyServer(function(input, output, clientData, session) { 
           output$lastSlider<- renderUI({
             k <- as.integer(input$order)
             l <- as.integer(input$iknots) 
             sliderInput("xi1",label =  withMathJax(paste0("\\(\\xi_{", k + l, "}\\)")), min = 0, max = 10, step = 0.1,value=input$xi1)
           })

         }))

你有什么想法为什么会这样？这是输出sessionInfo()：

R version 3.4.4 (2018-03-15)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

Matrix products: default

locale:
[1] LC_COLLATE=German_Austria.1252  LC_CTYPE=German_Austria.1252    LC_MONETARY=German_Austria.1252
[4] LC_NUMERIC=C                    LC_TIME=German_Austria.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] shiny_1.0.5

loaded via a namespace (and not attached):
 [1] compiler_3.4.4  R6_2.2.2        htmltools_0.3.6 tools_3.4.4     yaml_2.1.16     Rcpp_0.12.16   
 [7] jsonlite_1.5    digest_0.6.13   xtable_1.8-2    httpuv_1.3.5    mime_0.5   

提前致谢。

标签： rshinymathjax

Answer 1

像这样：

library(shiny)
shinyApp(

  ui = shinyUI(
    fluidPage(
      withMathJax(),
      sliderInput("order", "Order, \\(k\\)", min = 3, max = 7, value = 4, step = 1), 
      sliderInput("iknots", "iKnots", min = 0, max = 10, value = 5, step = 1),
      uiOutput("lastSlider")
    )
  ), 

  server = shinyServer(function(input, output, clientData, session) { 
    output$lastSlider<- renderUI({
      k <- as.integer(input$order)
      l <- as.integer(input$iknots) 
      tagList(
        withMathJax(),
        sliderInput("xi1", label = paste0("\\(\\xi_{", k + l, "}\\)"), 
                    min = 0, max = 10, step = 0.1, value=input$xi1)
      )
    })

  }))