尝试创建Shiny应用程序时出现错误

我快速浏览了您的代码，并提出了一些建议。

1）提供数据集时，可以使用函数dput（）-这将写出data.frame的文本表示形式，回答问题的人们可以简单地将其粘贴到R中。例如：

dput(final.plot)

这将产生文本输出，我可以通过final.plot <-在输出之前添加前缀来将其分配给数据框。我已经重新创建了您的数据框，并使用dput（）将其输出为以下文本。现在，其他用户可以快速剪切并粘贴您的数据：

请注意，此数据集有问题-参见下文

final.plot <- structure(list(id = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = "Ashmore and Cartier Islands", class = "factor"), 
                             long = c(123.1169, 123.1206, 123.1222, 123.1239, 123.1258, 123.1275),
                             lat = c(-12.25333, -12.25611, -12.25861, -12.25528, -12.25333, -12.25619),
                             order = 1:6, hole = c(FALSE, FALSE, FALSE, FALSE, FALSE, FALSE),
                             piece = c(1L, 1L, 1L, 1L, 1L, 1L),
                             group = structure(c(1L, 1L, 1L, 1L, 1L, 1L),
                             .Label = "Ashmore and Cartier Islands.1", class = "factor"), 
                             Population = c(NA, NA, NA, NA, NA, NA),
                             Density = c(NA, NA, NA, NA, NA, NA)),
                             .Names = c("id", "long", "lat", "order", "hole", "piece", "group", "Population", "Density"),
                             class = "data.frame",
                             row.names = c(NA, -6L))

错误“提供给连续刻度的离散值”是由两个问题引起的。

i）您在“人口”和“密度”列中均通过了NA。下面的数据框在这些列中添加了一些（不切实际的）数字，并且当我单独运行绘图代码时，错误已被消除。

更正的玩具数据集

final.plot <- structure(list(id = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = "Ashmore and Cartier Islands", class = "factor"), 
                             long = c(123.1169, 123.1206, 123.1222, 123.1239, 123.1258, 123.1275),
                             lat = c(-12.25333, -12.25611, -12.25861, -12.25528, -12.25333, -12.25619),
                             order = 1:6, hole = c(FALSE, FALSE, FALSE, FALSE, FALSE, FALSE),
                             piece = c(1L, 1L, 1L, 1L, 1L, 1L),
                             group = structure(c(1L, 1L, 1L, 1L, 1L, 1L),
                                               .Label = "Ashmore and Cartier Islands.1", class = "factor"), 
                             Population = c(1, 2, 3, 4, 5, 6),
                             Density = c(7, 3, 9, 1, 3, 6)),
                        .Names = c("id", "long", "lat", "order", "hole", "piece", "group", "Population", "Density"),
                        class = "data.frame",
                        row.names = c(NA, -6L))

ii）交互式运行时，由于未传递适当的数据来填充而导致错误fill = input$pop。您应该从final.plot $ Population或final.plot $ Density传递值，具体取决于所选内容。相反，您传递的是下拉框的输出-“人口”或“密度”。可以使用renderPlot中的switch语句来更正此错误：

# User input assigns appropriate data to selectedData which can be passed to other functions:
  selectedData <- switch(input$pop, 
                   "Population" = final.plot$Population,
                   "Density" = final.plot$Density)

2）如果您可以提供生成上面在“更新”中显示的静态地图的代码，将很有帮助。在调试Shiny代码时，我发现最简单的方法是先使该功能以非交互方式工作，然后再将其合并到Shiny中。我试图在下面提取您的绘图代码，但未产生预期的结果：

library(ggplot2) #Loading necessary libraries
library(mapproj)
library(maps)
ggplot() +
  geom_polygon(data = final.plot, 
               [![aes(x = long, y = lat, group = group, fill = Population), 
               color = "black", size = 0.25) + 
  coord_map()+
  scale_fill_distiller(name="Density", palette = "Spectral")+
  labs(title="Population in Australia")`

3）我对将数据绘制到R中的地图上并不熟悉，但是我相信您的应用程序需要加载到library（mapproj）和library（maps）中才能获得所需的结果。以上是所有内容的总和：

library(shiny)
library(ggplot2) #Loading necessary libraries
#I added the two lines below:
library(mapproj) 
library(map)

ui <- fluidPage(

  selectInput("pop",
              label="Type of Plot",
              choices=list("Population", "Density"),
              selected="Population"), #NOTE: Total Population changed to Population so that it selects correct default value

  plotOutput("curv") #Giving an input name and listing out types to choose in the Shiny app
)

server <- function(input, output){

#You will probably want to simply import your dataframe final.plot using read.table etc:      
final.plot <- structure(list(id = structure(c(1L, 1L, 1L, 1L, 1L, 1L), .Label = "Ashmore and Cartier Islands", class = "factor"), 
                                   long = c(123.1169, 123.1206, 123.1222, 123.1239, 123.1258, 123.1275),
                                   lat = c(-12.25333, -12.25611, -12.25861, -12.25528, -12.25333, -12.25619),
                                   order = 1:6, hole = c(FALSE, FALSE, FALSE, FALSE, FALSE, FALSE),
                                   piece = c(1L, 1L, 1L, 1L, 1L, 1L),
                                   group = structure(c(1L, 1L, 1L, 1L, 1L, 1L),
                                                     .Label = "Ashmore and Cartier Islands.1", class = "factor"), 
                                   Population = c(1, 2, 3, 4, 5, 6),
                                   Density = c(7, 3, 9, 1, 3, 6)),
                              .Names = c("id", "long", "lat", "order", "hole", "piece", "group", "Population", "Density"),
                              class = "data.frame",
                              row.names = c(NA, -6L))

  output$curv <- renderPlot({
    #Assign value of selectedData based upon user input:
    selectedData <- switch(input$pop, 
                   "Population" = final.plot$Population,
                   "Density" = final.plot$Density)
    ggplot() +
      geom_polygon(data = final.plot, 
                   aes(x = long, y = lat, group = group, fill =  selectedData), 
                   color = "black", size = 0.25) + 
      coord_map()+
      scale_fill_distiller(name="Density", palette = "Spectral")+
      labs(title="Population in Australia")
  })
}
shinyApp(ui = ui, server = server)

现在，您所需要做的就是替换代码，该代码将生成更新中显示的静态映射，以替换闪亮的应用程序中renderPlot中的错误代码。