r - 如何构建一个长的 selectInput 列表，然后使用它来更改 facet_wrap 中的标签

Question

这个问题引用了This SO question

上面的问题是关于更改 facet_wrap 的标签，答案是完美的 --> 将修改后的标签添加为数据集的新列。

现在，我面临的问题是——

用户选择多个变量 selectInput("select", h4("Variables:"), choices=var.both1(), selected=var.both1()[1], multiple=T, width="100%")
(例如:让我们考虑 input$select 长度可以是 6)
现在 input$select包含六个变量，我想检查每个变量并为其分配单位，我可以使用以下 react 组件部分实现这一点

variableunit <- reactive ({
  if(input$select == "TEPC") {"degC"}
  else if(input$select == "AT"){"µmol/kg"}
  else if(input$select == "DIC" | input$select == "DIN" | input$select == "PIC" | input$select == "POC" | input$select == "PON" | input$select == "POP" | input$select == "DOC" | input$select == "DON" | input$select == "DOP" | input$select == "TEP"){c("µmol/L")}
  else if(input$select == "Chla"){"µg/L"}
  else ("Meters")  
})

variableunit这里得到一个单一的值，即使用户输入了 6 个变量， variableunit只能给我一个值。

我怎么能在 variableunit 里面有一个包含 6 个值的列表这样我就可以在下面的 ggplot facet_wrap 中使用它

代码

    server <- function(input, output) {

  a <- reactive({
    fileinput1 <- input$file1
    if (is.null(fileinput1))
      return(NULL)
    read.table(fileinput1$datapath, header = TRUE, col.names = c("Ei","Mi","hours","Nphy","Cphy","CHLphy","Nhet","Chet","Ndet","Cdet","DON","DOC","DIN","DIC","AT","dCCHO","TEPC","Ncocco","Ccocco","CHLcocco","PICcocco","par","Temp","Sal","co2atm","u10","dicfl","co2ppm","co2mol","pH"))
    #read.table(fileinput1$datapath, header = TRUE, col.names =  c("Experiment","Mesocosm","Hour","Nphy","Cphy","CHLphy","Nhet","Chet","Ndet","Cdet","DON","DOC","DIN","DIC","AT","dCCHO","TEPC","Ncocco","Ccocco","CHLcocco","PICcocco","PAR","Temperature","Salinity","CO2atm","u10","DICflux","CO2ppm","CO2mol","pH"))  
    #a$Chla <- a$CHLphy + a$CHLcocco  #Add new columns as per observation data
    #a$PON <- a$Nphy + a$Nhet + a$Ndet + a$Ncocco 
  })

  output$showMapPlot <- renderUI({
{ list(plotOutput("plot",height="100%"), br()) }
  })



  output$select <- renderUI({
    if(!is.null(a())){selectInput("select", h4("Variables:"), choices=names(a()), selected=NULL, multiple=T, width="100%")}
  })


variableunit <- reactive ({
  if(input$select == "TEPC") {"degC"}
  else if(input$select == "AT"){"µmol/kg"}
  else if(input$select == "DIC" | input$select == "DIN" | input$select == "PIC" | input$select == "POC" | input$select == "PON" | input$select == "POP" | input$select == "DOC" | input$select == "DON" | input$select == "DOP" | input$select == "TEP"){c("µmol/L")}
  else if(input$select == "Chla"){"µg/L"}
  else ("Meters")  
})


  plot_4 <- function(var1 = input$select[1], var2 = input$select[2], var3 = input$select[3], var4 = input$select[4], var5 = input$select[5], var6 = input$select[6]) {
    myvars <- c(var1,var2,var3,var4,var5,var6)
    withProgress(message = 'Processing please wait...', value = 0, {
    gg4 <- aggregate(cbind(get(var1),get(var2),get(var3),get(var4),get(var5),get(var6))~Mi+hours,a(), FUN=mean)
    names(gg4)[3] <- var1
    names(gg4)[4] <- var2
    names(gg4)[5] <- var3
    names(gg4)[6] <- var4
    names(gg4)[7] <- var5
    names(gg4)[8] <- var6
    dd <- melt(gg4,id.vars=c("Mi","hours"), measure.vars=myvars)
    dd$label <- paste(as.character(dd$variable), "(", (variableunit()), ")", sep="")
    print(ggplot(dd,aes(x=hours, y=value)) + 
            geom_point(aes(color=factor(Mi)), size = 3, position = position_jitter(width = 0.1))  +
            geom_smooth(stat= "smooth" , alpha = I(0.01), method="loess", color = "blue") +
            facet_wrap(~label, nrow=3, ncol=2,scales = "free_y") + scale_color_discrete("Mesocosm") )
})
  }

  output$plot <- renderPlot({
    if(length(input$select) == 6){
    plot_4() 
    }
},
height=700, width=1100
)
}

ui <- shinyUI(fluidPage(
  fluidRow(column(3,
      uiOutput("showMapPlot"),
      wellPanel(
        h4("Data Upload"),
        fileInput('file1', h5('Choose Your Model Data'), accept=c('text/csv','text/comma-separated-values,text/plain','.OUT'))),
      wellPanel(h4("Variable selection"),uiOutput("select"))

    ),
    column(9,
           tabsetPanel(
             tabPanel("Conditional Plots",plotOutput("plot",height="auto"),value="barplots"),
             id="tsp"))
  )
))

shinyApp(ui = ui, server = server)

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只需复制粘贴代码并执行它。

现在问题
是第一个变量单元在所有其他图中重复。我知道这是我用来获取变量单位的 react 组件的问题。

问题
现在是，如何做到这一点？

我被困在这里很长时间了，真的希望有人知道解决方法。谢谢。

Answer 1

问:“如何在 variableunit 中拥有 6 个值的列表，以便我可以在下面的 ggplot facet_wrap 中使用它”

答:您可以在 react 函数中拥有 6 个值的列表。使用for循环遍历input$select .并将相应的单元保存到列表中的相同索引中。

server <- function(input, output) {

      variableunit <- reactive({
      test <- c("TEPC", "Chla", "DIN", "PIC", "AI", "PON")    
      values <- list()
      for(i in 1:length(test)) {

        if(test[[i]] == "TEPC") {
        values[[i]] <-"degC"
        }else if(test[[i]] == "AT"){
        values[[i]] <-"µmol/kg"
        }else if(test[[i]] == "DIC" | test[[i]] == "DIN" | test[[i]] == "PIC" | test[[i]] == "POC" | test[[i]] == "PON" | test[[i]] == "POP" | test[[i]] == "DOC" | test[[i]] == "DON" | test[[i]] == "DOP" | test[[i]] == "TEP"){
        values[[i]] <-"µmol/L"
        }else if(test[[i]] == "Chla"){
        values[[i]] <-"µg/L"
        }else{
        values[[i]] <-"Meters"
        }   
    }

  return(paste(as.character(test), "(",values,")", sep=""))
})

      output$text <- renderText({
        variableunit()
        print(paste(variableunit()))
      })
    }

    ui <- shinyUI(fluidPage(
      sidebarLayout(
        sidebarPanel(

        ),
        mainPanel(textOutput("text"))
      )
    ))

    shinyApp(ui = ui, server = server)

此示例呈现文本: TEPC(degC) Chla(µg/L) DIN(µmol/L) PIC(µmol/L) AI(Meters) PON(µmol/L)