R Shiny 中的 Ggplot2 圖，根據用戶輸入帶有線條

Question

我想使用ggplot2在我的 Shiny App 中制作一個圖表，該圖表根據主題繪制有關用戶選擇的線條。 在這個問題中，我被告知如何在給定主題沒有任何項目的情況下添加這些 0（使用 ankrun 的答案）。 現在我正在尋找在一個閃亮的應用程序中擬合這個圖表並考慮添加一個滑塊輸入，您可以在其中選擇該行的主題。 這是我嘗試過的：

# # # global # # #
#1. App
if("shiny" %in% rownames(installed.packages()) == FALSE){ install.packages("shiny") }
library(shiny)
#2. Easier data handling
if("dplyr" %in% rownames(installed.packages()) == FALSE){ install.packages("dplyr") }
library(dplyr)
#3. Graphs
if("ggplot2" %in% rownames(installed.packages()) == FALSE){ install.packages("ggplot2") }
library(ggplot2)
#4. Completion in graphs
if("tidyr" %in% rownames(installed.packages()) == FALSE){ install.packages("tidyr") }
library(tidyr)

# # # ui # # #
ui <- fluidPage( 
  sidebarPanel(
    selectInput("select_topic_timeline", "What topic?",
                choices = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"), 
                selected =  c("1", "2", "3", "4","5", "6", "7", "8", "9", "10", "11", "12"),
                multiple = T)
  ),#sidebarPanel
  mainPanel( 
    plotOutput("per_topic_timeline")
  ) #mainPanel
) #fluidPage

# # # server # # #
server <- function(input, output, session) {

  # TIMELINE PER TOPIC PER YEAR
  output$per_topic_timeline <- renderPlot({
  dtd2 <- structure(list(Topic = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
                                             1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
                                             3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
                                             5L, 5L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 
                                             7L, 7L, 8L, 8L, 8L, 8L, 8L, 8L, 8L, 8L, 9L, 9L, 9L, 9L, 9L, 9L, 
                                             10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 11L, 11L, 11L, 11L, 
                                             11L, 11L, 11L, 11L, 11L, 12L, 12L, 12L, 12L, 12L, 12L, 12L), .Label = c("Topic 1", 
                                                                                                                     "Topic 10", "Topic 11", "Topic 12", "Topic 2", "Topic 3", "Topic 4", 
                                                                                                                     "Topic 5", "Topic 6", "Topic 7", "Topic 8", "Topic 9"), class = "factor"), 
                         Year = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 2L, 
                                            3L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 
                                            3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 
                                            9L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 
                                            8L, 9L, 1L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 6L, 7L, 8L, 
                                            9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 
                                            6L, 7L, 8L, 9L, 2L, 3L, 4L, 5L, 6L, 7L, 8L), .Label = c("2011", 
                                                                                                    "2012", "2013", "2014", "2015", "2016", "2017", "2018", "2019"
                                            ), class = "factor"), Count = c(3L, 3L, 3L, 5L, 5L, 11L, 
                                                                            17L, 14L, 4L, 1L, 1L, 4L, 2L, 3L, 9L, 4L, 2L, 1L, 3L, 4L, 
                                                                            5L, 18L, 23L, 19L, 15L, 1L, 5L, 6L, 8L, 11L, 17L, 7L, 1L, 
                                                                            3L, 6L, 4L, 20L, 21L, 18L, 12L, 3L, 1L, 1L, 2L, 5L, 5L, 11L, 
                                                                            5L, 2L, 1L, 1L, 2L, 2L, 5L, 7L, 23L, 9L, 1L, 1L, 2L, 3L, 
                                                                            6L, 4L, 9L, 8L, 1L, 1L, 6L, 2L, 3L, 3L, 1L, 3L, 2L, 5L, 7L, 
                                                                            11L, 11L, 28L, 11L, 2L, 1L, 2L, 2L, 5L, 6L, 5L, 16L, 3L, 
                                                                            4L, 2L, 2L, 7L, 6L, 8L, 6L)), row.names = c(NA, -96L), class = "data.frame")

  dtd2 %>%
      expand(Topic = factor(Topic, levels = gtools::mixedsort(levels(c(input$select_topic_timeline)))) ,
             Year = unique(Year)) %>% 
      left_join(dtd2) %>% 
      mutate(Count = replace_na(Count, 0)) %>%
      ggplot(aes(x = Year, y = Count), colour = c(input$select_topic_timeline), group = Topic) + 
      geom_point() +
      geom_line() +
      labs(x = "Year", y = NULL, title = "Timeline")
  })
}

shinyApp(ui,server)

它沒有打印任何錯誤，但它說Warning: Column "Topic" joining factors with different levels, coercing to character vector ，並且沒有給出任何圖形，只有一個空的灰色框。 我不確定如何在圖形代碼中擬合輸入，我一定是改錯了！

Answer 1

這個問題是您基本上是根據selectInput內容重構dtd2$Topic ，但由於Topic只有 9 個級別，並且您最多可以使用selectInput選擇 12 個級別，因此您會收到錯誤。

出於這個原因，我建議改用@Ronak Shah 的回答與tidyr::complete代替。

completed數據后，您應該dplyr::filter by Topic 以獲得我認為是所需的結果：

# # # global # # #
#1. App
if("shiny" %in% rownames(installed.packages()) == FALSE){ install.packages("shiny") }
library(shiny)
#2. Easier data handling
if("dplyr" %in% rownames(installed.packages()) == FALSE){ install.packages("dplyr") }
library(dplyr)
#3. Graphs
if("ggplot2" %in% rownames(installed.packages()) == FALSE){ install.packages("ggplot2") }
library(ggplot2)
#4. Completion in graphs
if("tidyr" %in% rownames(installed.packages()) == FALSE){ install.packages("tidyr") }
library(tidyr)

# # # ui # # #
ui <- fluidPage( 
  sidebarPanel(
    selectInput("select_topic_timeline", 
                label = "What topic?",
                choices = as.character(1:12), 
                selected = as.character(1:12),
                multiple = TRUE),
  ),#sidebarPanel
  mainPanel( 
    plotOutput("per_topic_timeline")
  ) #mainPanel
) #fluidPage

# # # server # # #
server <- function(input, output, session) {

  # TIMELINE PER TOPIC PER YEAR
  output$per_topic_timeline <- renderPlot({
    dtd2 <- structure(list(Topic = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
                                               1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
                                               3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
                                               5L, 5L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 7L, 7L, 7L, 7L, 7L, 7L, 7L, 
                                               7L, 7L, 8L, 8L, 8L, 8L, 8L, 8L, 8L, 8L, 9L, 9L, 9L, 9L, 9L, 9L, 
                                               10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 10L, 11L, 11L, 11L, 11L, 
                                               11L, 11L, 11L, 11L, 11L, 12L, 12L, 12L, 12L, 12L, 12L, 12L), .Label = c("Topic 1", 
                                                                                                                       "Topic 10", "Topic 11", "Topic 12", "Topic 2", "Topic 3", "Topic 4", 
                                                                                                                       "Topic 5", "Topic 6", "Topic 7", "Topic 8", "Topic 9"), class = "factor"), 
                           Year = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 2L, 
                                              3L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 
                                              3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 
                                              9L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 
                                              8L, 9L, 1L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 6L, 7L, 8L, 
                                              9L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 4L, 5L, 
                                              6L, 7L, 8L, 9L, 2L, 3L, 4L, 5L, 6L, 7L, 8L), .Label = c("2011", 
                                                                                                      "2012", "2013", "2014", "2015", "2016", "2017", "2018", "2019"
                                              ), class = "factor"), Count = c(3L, 3L, 3L, 5L, 5L, 11L, 
                                                                              17L, 14L, 4L, 1L, 1L, 4L, 2L, 3L, 9L, 4L, 2L, 1L, 3L, 4L, 
                                                                              5L, 18L, 23L, 19L, 15L, 1L, 5L, 6L, 8L, 11L, 17L, 7L, 1L, 
                                                                              3L, 6L, 4L, 20L, 21L, 18L, 12L, 3L, 1L, 1L, 2L, 5L, 5L, 11L, 
                                                                              5L, 2L, 1L, 1L, 2L, 2L, 5L, 7L, 23L, 9L, 1L, 1L, 2L, 3L, 
                                                                              6L, 4L, 9L, 8L, 1L, 1L, 6L, 2L, 3L, 3L, 1L, 3L, 2L, 5L, 7L, 
                                                                              11L, 11L, 28L, 11L, 2L, 1L, 2L, 2L, 5L, 6L, 5L, 16L, 3L, 
                                                                              4L, 2L, 2L, 7L, 6L, 8L, 6L)), row.names = c(NA, -96L), class = "data.frame")

    dtd2 %>%
      complete(Topic, Year = unique(Year), fill = list(Count = 0)) %>% 
      filter(Topic %in% paste("Topic", input$select_topic_timeline)) %>% 
      ggplot(aes(x = Year, y = Count, colour = Topic, group = Topic)) + 
      geom_point() +
      geom_line() +
      labs(x = "Year", y = NULL, title = "Timeline")
  })
}

shinyApp(ui,server)

作為旁注，我還建議對這個特定的輸入使用shinyWidgets包，特別是shinyWidgets::pickerInput ，而不是普通的shinyWidgets::pickerInput shiny::selectInput 。 不過，我會把這個決定留給你。