我正在尝试使用 if 语句Shiny.

我想在外部使用“min”和“name”变量for() loop.

我试过把if()中的声明reactive但随后我无法访问“min”和“name”变量。

Code:

server=function(input, output){
  
cord <- reactive({matrix(c(input$long,input$lat),nrow=1,ncol=2)})

min=reactive({distHaversine(c(b[1,2],b[1,3]),c(cord[,1],cord[,2]))})

for (i in 1:15){
  distance=reactive({distHaversine(c(b[i,2],b[i,3]),c(cord[,1],cord[,2]))})
 

  if(distance() < min())
  {
  min=distance()
  name=reactive({CO[i,1]})
  }
}

data=reactive({name()})
output$table<-renderTable(data())
}

shinyApp(ui=ui,server=server)

根据您的新机票表名而不是显示的表 R Shiny https://stackoverflow.com/questions/49111594/table-name-and-not-table-being-displayed-r-shiny

library(shiny)

ui <- fluidPage(renderTable("table"))

server <- function(input, output, session){

  v <- reactiveValues()

  cord <- reactive({
    req(input$long)
    req(input$lat)
    mc <- matrix(c(input$long,input$lat),nrow=1,ncol=2)
    v$ans <- distHaversine(mc(b[1,2],b[1,3]),c(mc[,1],mc[,2]))
    mc
  })

  data <- reactive({

    for(i in 1:15){
      distance <- distHaversine(c(b[i,2],b[i,3]),c(cord()[,1],cord()[,2]))

      if(distance < v$ans){
        v$ans <- distance
        return(CO[i,1])
      }
    }
  })

  output$table <- renderTable({
    data()
  })
}

shinyApp(ui=ui,server=server)