Question

我正在尝试编写一个闪亮的应用程序，并且对R codin来说相当新。我正在阅读包含3列的.txt文件。一列是日期，另外两列是数字（日期列被读作类字符。文本文件由用户选择的名称选择。服务器比在x轴上绘制日期和数字值在y轴。我还添加了缩放功能。当未声明日期列时，应用程序正常工作（因此删除行时，日期将绘制为字符）。当Date列被以下代码声明为日期时：

 inlees$Date <- dmy(inlees$Date) #convert from character to Date

该应用程序返回错误：

错误：ggplot2不知道如何处理类Date的数据

Snapshot of the text file can be found here 任何帮助表示赞赏。

我使用以下脚本：

UI

    ui <- fluidPage(selectInput(inputId = "name", label = "Selecteer    analyse", choices=c("TESTOSTERON", 
                        "ANDROSTEENDION", "17OHProgesteron", "P4")),

            plotOutput("p1", dblclick = "p1_dblclick",
                brush = brushOpts(id = "p1_brush", resetOnNew = TRUE)),

            plotOutput("p2", dblclick = "p2_dblclick",
                       brush = brushOpts(id = "p2_brush", resetOnNew = TRUE)))

服务器

    server <- function(input, output) {

    rangesp1 <- reactiveValues(y = NULL)

    selectData <-  reactive ({

    data_path <- "ANPR"   # path to the data
    inlees <- input$name
    files <- dir(data_path, pattern = paste0(inlees,".*\\.txt")) # get file names

  inlees <- files %>%
  # read in all the files, appending the path before the filename
  map(~ read_tsv(file.path(data_path, .), skip = 6, col_names = TRUE))%>% 
  reduce(rbind)

inlees$Date <- dmy(inlees$Date) #convert from character to Date
})

output$p1 <- renderPlot({

p1 <- ggplot(data = selectData(), aes(x = Date, y = Ratio)) + geom_point(color = "#1874CD80") +
  ylab(expression("D0 Ratio")) + theme_bw() + xlab("Date") +
  theme(axis.title.y = element_text(size = 12),axis.text = element_text(size = 12),
        axis.title.x = element_text(size = 12), panel.grid.major = element_blank(), 
        axis.line = element_line(colour = "black"),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank()) +
coord_cartesian(ylim = rangesp1$y)
      p1 })

observeEvent(input$p1_dblclick, {
brush <- input$p1_brush
if (!is.null(brush)) {

  rangesp1$y <- c(brush$ymin, brush$ymax)

} else {

  rangesp1$y <- NULL
}
})

rangesp2 <- reactiveValues(y = NULL)
output$p2 <- renderPlot({


p2 <- ggplot(data = selectData(), aes(x = Date, y = ISArea)) + geom_point(color = "#68228B80") +
  ylab(expression("IS Area")) + theme_bw() + xlab("Date") +
  theme(axis.title.y = element_text(size = 12),axis.text = element_text(size = 12),
        axis.title.x = element_text(size = 12), panel.grid.major = element_blank(), 
        axis.line = element_line(colour = "black"),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank()) +
  coord_cartesian(ylim = rangesp2$y)
  p2
  })


  observeEvent(input$p2_dblclick, {
  brush <- input$p2_brush
  if (!is.null(brush)) {

    rangesp2$y <- c(brush$ymin, brush$ymax)

  } else {    
    rangesp2$y <- NULL
  }
    })

 }

 shinyApp(ui = ui, server = server)

Answer 1

我是明确的return语句的粉丝，这可能是为什么使用return()是一个好习惯的好例子。

?function的帮助页面说：

如果在没有调用return的情况下到达函数的结尾，则返回最后一个计算表达式的值。

现在，定义selectData函数的反应式表达式中的最后一个语句是：

inlees$Date <- dmy(inlees$Date)

因此，返回最后一个类Date - 而不是类data.frame - 的评估表达式，随后导致ggplot()中的错误。

请在return(inlees)表达式中添加reactive()作为最后一条语句：

selectData <-  reactive ({

  data_path <- "ANPR"   # path to the data
  inlees <- input$name
  files <- dir(data_path, pattern = paste0(inlees,".*\\.txt")) # get file names

  inlees <- files %>%
    # read in all the files, appending the path before the filename
    map(~ read_tsv(file.path(data_path, .), skip = 6, col_names = TRUE))%>% 
    reduce(rbind)

  inlees$Date <- dmy(inlees$Date) #convert from character to Date
  return(inlees)
})

Answer 2

感谢您的回复。非常感谢。从我的第一个问题中学到了很多东西。我尝试了你的解决方案Uwe，但后来我遇到了“ggplot2不知道如何处理列表”的错误。在您提出建议之后，我想，我也可以将列Date声明为“read_tsv”行中的日期，现在一切正常:)：

 inlees <- files %>%
  # read in all the files, appending the path before the filename
  map(~ read_tsv(file.path(data_path, .), skip = 6, col_names = TRUE, 
  col_types = cols(Date = col_date(format = "%d-%b-%y")))) %>% 
  reduce(rbind)

ggplot2不知道如何处理类Date

2 个答案: