在 R Shiny 中使用 renderTable 时如何格式化数字行输出？

Question

在运行以下 MWE 代码时呈现的 4 行表中，我希望前 2 行中的值以不带小数的形式呈现，而后 2 行中的值以带小数的形式呈现到百分之一和一个 % 符号。如最底部的图像所示，在第一次调用时的默认视图的情况下。这种格式适用于首次调用应用程序和修改它（添加/删除行）时呈现的默认表。

有没有一种有效的方法来做到这一点？如果可能的话，也许不添加函数（将其嵌入到下面的output$table3 <- renderTable(.. 部分中）？

MWE 代码：

library(shiny)
library(shinyMatrix)
library(magrittr)

# Default matrix for initializing
matrix3DefaultRownames <- c("A", "B", "C", "D")
matrix3Default <- data.frame('Series 1' = c(1, 24, 0, 100), row.names = matrix3DefaultRownames) %>% as.matrix()

matrix3Input <- function(inputId, matrix3Default) {
  matrixInput(
    inputId = inputId,
    label = "Input terms:",
    value = matrix3Default,
    rows = list(extend = FALSE, names = TRUE),
    cols = list(extend = TRUE, names = TRUE, editableNames = FALSE, delete = TRUE),
    class = "numeric"
  )
}

ui <- fluidPage(titlePanel("Inputs"), fluidRow(actionButton("modify", "Modify"), tableOutput("table3")))

server <- function(input, output, session) {
  rv <- reactiveValues(
    mat3 = matrix3Input("matrix3", matrix3Default),
    input = matrix3Default,
    colHeader = colnames(input)
  )
  
  observeEvent(input$modify, {
    showModal(modalDialog(rv$mat3))
  })
  
  output$table3 <- renderTable(
    {
      if (isTruthy(input$modify)) {
        req(input$matrix3)
        
        df <- input$matrix3
        rv$mat3 <- matrix3Input("matrix3", df)
        colnames(df) <- paste("Series", 1:ncol(df))
        rownames(df) <- matrix3DefaultRownames
        rv$input <- df
      } else {
        df <- matrix3Default
        colnames(df) <- paste("Series", 1:ncol(df))
        rownames(df) <- matrix3DefaultRownames
      }
      df
    },
    rownames = TRUE,
    colnames = TRUE
  )
}

shinyApp(ui, server)

Answer 1

@Ronak 的回答很好，但它改变了表格的值。我宁愿使用按列选项render，它允许在不更改值的情况下更改值的显示。

library(DT)

dat <- data.frame(
  x = c(
    1.2,
    24.3,
    0,
    0.999
  ),
  y = c(
    12.8,
    34.7,
    0.1,
    0.05
  )
)

js <- c(
  "function(data, type, row, meta){",
  "  var rowindex = meta.row;",
  "  if(type === 'display'){",
  "    if(rowindex <= 1){",
  "      return data.toFixed(0);",
  "    }else{",
  "      return (100*data).toFixed(2) + '%';",
  "    }",
  "  }",
  "  return data;",
  "}"
)

datatable(
  dat,
  options = list(
    columnDefs = list(
      list(targets = c(1, 2), render = JS(js))
    )
  )
)

Answer 2

您可以使用sprintf 执行此格式化 -

library(shiny)
library(shinyMatrix)
library(magrittr)

# Default matrix for initializing
matrix3DefaultRownames <- c("A", "B", "C", "D")
matrix3Default <- data.frame('Series 1' = c(1, 24, 0, 100), row.names = matrix3DefaultRownames) %>% as.matrix()

matrix3Input <- function(inputId, matrix3Default) {
  matrixInput(
    inputId = inputId,
    label = "Input terms:",
    value = matrix3Default,
    rows = list(extend = FALSE, names = TRUE),
    cols = list(extend = TRUE, names = TRUE, editableNames = FALSE, delete = TRUE),
    class = "numeric"
  )
}

ui <- fluidPage(titlePanel("Inputs"), fluidRow(actionButton("modify", "Modify"), tableOutput("table3")))

server <- function(input, output, session) {
  rv <- reactiveValues(
    mat3 = matrix3Input("matrix3", matrix3Default),
    input = matrix3Default,
    colHeader = colnames(input)
  )
  
  observeEvent(input$modify, {
    showModal(modalDialog(rv$mat3))
  })
  
  output$table3 <- renderTable(
    {
      if (isTruthy(input$modify)) {
        req(input$matrix3)
        
        df <- input$matrix3
        rv$mat3 <- matrix3Input("matrix3", df)
        colnames(df) <- paste("Series", 1:ncol(df))
        rownames(df) <- matrix3DefaultRownames
        rv$input <- df
      } else {
        df <- matrix3Default
        colnames(df) <- paste("Series", 1:ncol(df))
        rownames(df) <- matrix3DefaultRownames
      }
      df[3:4] <- sprintf('%.2f%%', df[3:4])
      #If you don't want to hardcode 3rd and 4th row and select only last2 rows.
      #n <- nrow(df)
      #df[c(n-1, n)] <- sprintf('%.2f%%', df[c(n-1, n)])
      df
    },
    rownames = TRUE,
    colnames = TRUE
  )
}

shinyApp(ui, server)