在我闪亮的应用服务器部分制作 if 语句

Question

希望您能帮助我在 R 中使用 Shiny 应用程序。我是 Shiny 的新手，需要一些帮助来简化我的后端部分。

我正在尝试基于两个输入呈现表格，一个是医院输入，第二个输入是请求的表格类型。为了得到我想要的表，我做了几个 if 语句，但代码似乎很复杂，可以简化。

基本上，我需要根据医院和表格类型为 Shiny 应用程序显示表格，而不需要太长的 if 语句。

有没有人可以帮助我编写下面的代码以使其更简单。

library(shiny)
library(tidyverse)



UCSF <- list( ndc_ucsf_v2, brand_n_v2, ndc_tier2_ucsf_v2, ndc_tier5_ucsf_v2, ucsf_ldd_list_v2,
              brand_n_class_ucsf_v2, ndc_rest_of_tiers_ucsf_v2)

hospital_list <- c("UCSF", "VIDANTHEALTH", "CONH", "ERLR", "OSURX", "SUTTHEALTH",
                   "UHC", "WHT")
table_list <- c("By NDC", "By brand name", "By GPI class", "By tier 2", "By tier 5", "Other tiers",
                "LDD", "By hierarchy")
ui <- fluidPage(
    titlePanel("Hospital rebate claims"),

    # Sidebar with a slider input for number of bins 
    sidebarLayout(
        sidebarPanel(
            selectInput(inputId = "hospital", 
                        label = "Hostpital/clinic", 
                        choices = c("Choose hospital", hospital_list),
                        multiple = FALSE),
            selectInput(inputId = "table_type", 
                        label = "Type of analysis",
                        multiple = FALSE, choices = table_list)),
                mainPanel(
           tableOutput(outputId = "claimtable"),
           plotOutput(outputId = "hist")
)))

server <- function(input, output) {
      output$claimtable <- renderTable({
      if(input$hospital == "UCSF" & input$table_type == "By NDC"){
        output$claimtable <- return(UCSF[[1]])
        } 
        if(input$hospital == "UCSF" & input$table_type == "By brand name") {
        output$claimtable <- return(UCSF[[2]])
        }
        if(input$hospital == "UCSF" & input$table_type == "By tier 2") {
          output$claimtable <- return(UCSF[[3]])
        }
        if(input$hospital == "UCSF" & input$table_type == "By tier 5") {
          output$claimtable <- return(UCSF[[4]])
        }
        if(input$hospital == "UCSF" & input$table_type == "LDD") {
          output$claimtable <- return(UCSF[[5]])
        }
        if(input$hospital == "UCSF" & input$table_type == "By GPI class") {
          output$claimtable <- return(UCSF[[6]])
        }
        if(input$hospital == "UCSF" & input$table_type == "Other tiers") {
          output$claimtable <- return(UCSF[[7]])
        }})
}

shinyApp(ui = ui, server = server)

Answer 1

您可以使用switch 而不是重复if 命令：

server <- function(input, output) {
  output$claimtable <- renderTable({
    
    if (input$hospital == "UCSF") {
      switch (input$table_type,
              "By NDC" = UCSF[[1]],
              "By brand name" = UCSF[[2]],
              "By tier 2" = UCSF[[3]],
              "By tier 5" = UCSF[[4]],
              "LDD" = UCSF[[5]],
              "By GPI class" = UCSF[[6]],
              "Other tiers" = UCSF[[7]],
      )
    } else {
      # What happens here? 
      # You example doesn't show it
    }
    
  }

或者，您也可以正确订购 table_list 并根据它进行替换：

table_list <- c("By NDC", "By brand name", "By tier 2", "By tier 5",
                  "LDD", "By GPI class", "Other tiers", "By hierarchy")
    
server <- function(input, output) {
    output$claimtable <- renderTable({
      
      if (input$hospital == "UCSF") {
        UCSF[[which(table_list == input$table_type)]]
      } else {
        # What happens here? 
        # You example doesn't show it
      }
      
    }

input$hospital 有什么变化？也许它改变了列表的第二级？

server <- function(input, output) {
  output$claimtable <- renderTable({
    UCSF[which(table_list == input$table_type)][which(hospital_list == input$hospital_list)]
    
  }