R：使用单选按钮的输入作为by（）中的参数

我有一个简单的单选按钮，允许用户选择“区域”或“房间大小”。我希望输入被传递到by（）的index参数，这样我就可以为数据帧的每个因子级别运行一个函数，并在表中呈现结果

我试过的几件事是：

 df <- Heating
 output$allmodelsbychar <- renderTable({    
    var <- input$runallmodels

    betas <- by(df, df$var, function(df){as.data.frame(summary(mlogit(depvar ~ ic + oc | 0, data= df, shape = "wide", choice = "depvar", varying = c(3:12)))$CoefTable)}, simplify = T)
    betas <- do.call("rbind", betas)
    betas
  })   
}

---

df我使用
if eles解决了这个问题

server <- function(input, output) {

  df <- Heating
output$allmodelsbychar <- renderTable({

dfindecies <- reactive({
  if (input$runallmodels == "regiontype") {
    df <- df[, 16]
  } else {
    df <- df[, 15]
    return(df)
  }
})

### Do stuff

  }) 



}

服务器
df <- Heating
 output$allmodelsbychar <- renderTable({

dfindecies <- reactive({
  if (input$runallmodels == "regiontype") {
    df <- df[, 15]
  }

  if (input$runallmodels == "roomsize") {
    df <- df[, 16]
    return(df)
  }
})

betas <- by(df, dfindecies(), function(df){as.data.frame(summary(mlogit(depvar ~ ic + oc | 0, data= df, shape = "wide", choice = "depvar", varying = c(3:12)))$CoefTable)}, simplify = T)
betas <- do.call("rbind", betas)
betas

server <- function(input, output) {

  df <- Heating
output$allmodelsbychar <- renderTable({

dfindecies <- reactive({
  if (input$runallmodels == "regiontype") {
    df <- df[, 16]
  } else {
    df <- df[, 15]
    return(df)
  }
})

### Do stuff

  }) 



}