图没有出现

Question

我正在尝试创建一个图表，我可以在其中按年份查看总航班数，并按出发地和目的地进行过滤。 Picture1: What I envision VS Picture2: The result.

问题一：图表无法出现在 shinyApp 上。

问题 2：当图表出现时，即使我 select 来自下拉框的不同来源，图表也没有改变

我对 shiny 很陌生，如有任何帮助，我们将不胜感激！我使用的数据来自哈佛数据库- data expo 2009, Airline on time data.

library(DBI)
library(ggplot2)
library(dplyr)
library(RSQLite)

#q3 data from sql
 q3m <- dbGetQuery(conn, "
SELECT Year, Origin, Dest, COUNT(FlightNum) AS Total
FROM ontime
WHERE Cancelled = 0 AND Diverted = 0
GROUP BY Origin,Dest,Year
")
q3m

#ggplot
q3plot <- ggplot(q3m) + 
  geom_col(aes(x= Year, y = Total))+ 
  scale_x_discrete(limits = c(2000,2001)) + 
  facet_wrap(~Dest) +
  labs(title = paste(q3m$Origin , "to" )  , x = "Year", y = "Total Flights") +
  geom_text(aes(x = Year, y = Total, label = Total), vjust = 1.5, size = 3.5, color = "white") 
q3plot

闪亮

library(shiny)
server <- function(input,output, session) {  
  #data
  data <- reactive({
    req(input$sel_q3)
    q3m
    })
  
  #plot
  output$plot <- renderPlot({
      q3plot <- ggplot(data(),aes(x= Year, y = Total)) + scale_x_discrete(limits = c(2000,2001)) + 
  facet_wrap(~Dest) +
  geom_col()
  })

  #update dynamically
  observe({
    updateSelectInput(session, "sel_q3", choices = q3m$Origin)
  })
 }



ui <- fluidPage(
      h1("Comparison of total flights of airport"),
      selectInput(inputId = "sel_q3",
                  label = "Select your airport",
                  "Names"),
      plotOutput("plot")
    )
    
    shinyApp(ui=ui, server = server)

SHINY 显示图表但图表没有改变

我所做的只是将 q3plot 放入 output$plot 而不是重新输入 ggplot

server <- function(input,output, session) {
  
  #data
  data <- reactive({
    req(input$sel_q3)
    q3m
    })
  
  #plot
  output$plot <- renderPlot({
      q3plot
  })

  #update dynamically
  observe({
    updateSelectInput(session, "sel_q3", choices = q3m$Origin)
  })
}


ui <- fluidPage(
  h1("Comparison of total flights of airport"),
  selectInput(inputId = "sel_q3",
              label = "Select your airport",
              "Names"),
  plotOutput("plot")

)
shinyApp(ui=ui, server = server)

Answer 1

感谢@MrFlick 如果有人遇到同样的问题，解决方案基本上是添加适当的过滤

#data
  data <- reactive({
    req(input$sel_q3)
    df <- q3m %>% filter(Origin %in% inputsel_q3)  # <- this is the fix
    })

#plot
  output$plot <- renderPlot({
      ggplot(data(),aes(x,y)) + geomcol()
  })

图没有出现

Graph is not appearing

r

ggplot2

shiny