如标题所述，我正在尝试使用 R 中的 Shiny 创建一个程序来读取用户上传的 csv 文件，之后用户可以从该文件中选择一个变量来查看绘制的图通过 ggplot。我试图通过两个选项卡实现这一点，第一个选项卡将读取文件，第二个选项卡将让用户选择变量以查看绘图。
我的代码如下。目前，我能够成功读取用户文件，但无法根据所选变量进行绘图(我目前只有 1 个变量“Location”用于演示)。 (HomeWTaxAmt 是要绘制的 y 变量)。
library(shiny)
library(ggplot2)
library(data.table)
library(RColorBrewer)
options(scipen=1000)
ui <- fluidPage(
navbarPage("User Interface:",tabPanel("Upload",
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(
fileInput("file1", "Choose CSV File",
multiple = TRUE,
accept = c("text/csv",
"text/comma-separated-values,text/plain",
".csv")),
tags$hr(),
checkboxInput("header", "Header", TRUE),
radioButtons("sep", "Separator",
choices = c(Comma = ",",
Semicolon = ";",
Tab = "\t"),
selected = ","),
tags$hr(),
radioButtons("disp", "Display",
choices = c(Head = "head",
All = "all"),
selected = "head"),
radioButtons("quote", "Quote",
choices = c(None = "",
"Double Quote" = '"',
"Single Quote" = "'"),
selected = '"')),
mainPanel(
verbatimTextOutput("summary"),
tableOutput("contents")
))),
tabPanel("Graphing",
titlePanel("Plotting Graphs"),
sidebarLayout(
sidebarPanel(
selectInput("variable", "Variable:",
list("Location"))),
mainPanel(
h3(textOutput("caption")),
plotOutput("ggplot")
)
))
))
server <- function(input, output) {
output$contents <- renderTable({
req(input$file1)
library(data.table)
data <- fread(input$file1$datapath,
header = input$header,
sep = input$sep,
quote = input$quote)
if(input$disp == "head") {
return(head(data))
}
else {
return(data)
}
})
output$summary <- renderPrint({
summary(data)
})
formulaText <- reactive(function() {
paste("HomeWTaxAmt ~", input$variable)
})
output$caption <- renderText(function() {
formulaText()
})
output$ggplot <- renderPlot(function() {
data <- fread(input$file1$datapath,
header = input$header,
sep = input$sep,
quote = input$quote)
if(is.null(data)) return(NULL)
# check for the input variable
ggplot(data, aes(x=reorder(factor(data[input$variable]), -abs(HomeWTaxAmt), function(x){sum(x)}),
weight = abs(HomeWTaxAmt), fill = factor(data[input$variable]))) + geom_bar(show.legend=FALSE) + xlab(input$variable) +
scale_fill_manual(values=brewer.pal(n = 12, name = "Paired"))
})
}
shinyApp(ui, server)
最佳答案
由于我无法访问您的确切 .csv 文件，我不得不对绘图命令进行一些调整，但我很确定您可以从那里开始并让它与您的数据一起使用。请注意，现在不加载 .csv 文件会在第一个选项卡上显示错误，这些错误会在数据加载后立即消失。您可能希望在此处使用一些 ifelse 开关来确保最终用户不必看到这些 R 错误。
这是根据我拥有的一些示例数据按预期绘制绘图的代码:
library(shiny)
library(ggplot2)
library(data.table)
library(RColorBrewer)
options(scipen=1000)
#XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
# I didn't change anything in this section
ui <- fluidPage(
navbarPage("User Interface:",tabPanel("Upload",
titlePanel("Uploading Files"),
sidebarLayout(
sidebarPanel(
fileInput("file1", "Choose CSV File",
multiple = TRUE,
accept = c("text/csv",
"text/comma-separated-values,text/plain",
".csv")),
tags$hr(),
checkboxInput("header", "Header", TRUE),
radioButtons("sep", "Separator",
choices = c(Comma = ",",
Semicolon = ";",
Tab = "\t"),
selected = ","),
tags$hr(),
radioButtons("disp", "Display",
choices = c(Head = "head",
All = "all"),
selected = "head"),
radioButtons("quote", "Quote",
choices = c(None = "",
"Double Quote" = '"',
"Single Quote" = "'"),
selected = '"')),
mainPanel(
verbatimTextOutput("summary"),
tableOutput("contents")
))),
tabPanel("Graphing",
titlePanel("Plotting Graphs"),
sidebarLayout(
sidebarPanel(
selectInput("variable", "Variable:",
list("Location"))),
mainPanel(
h3(textOutput("caption")),
plotOutput("ggplot")
)
))
))
#XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
server <- function(input, output, session) { # make sure to include "session" here, in order to update your inputs later
# create an reactive upload to access your data more quickly and easily
reactive_data <- reactive({
print(input$file1$datapath)
data <- fread(input$file1$datapath,
header = input$header,
sep = input$sep,
quote = input$quote)
return(data)
})
# preview
# no library(data.table) required here, as its already loaded at the beginning of the script)
output$contents <- renderTable({
# load your data
data <- reactive_data()
if(input$disp == "head") {
return(head(data))
}
else {
return(data)
}
})
output$summary <- renderPrint({
summary(reactive_data())
})
formulaText <- reactive({ # no need for function() here
paste("HomeWTaxAmt ~", input$variable)
})
output$caption <- renderText({
formulaText()
})
output$ggplot <- renderPlot({
# load your data
data <- reactive_data()
# to only plot when data is not NULL, make sure to include the plotting command in the if-else statement
# no data
if(is.null(data)){
return(NULL)
}else{
# data
# update your selectInput first, so that all the variables match your .csv headers
updateSelectInput(session, "variable",
choices = colnames(data),
selected = input$variable) # this keeps the input on the last thing selected on tab-change
# check for the input variable
# I used aes_string here so that indexing the colnames works
# you'll have to adjust the plotting command to your needs as my .csv files aren't the same as yours
plot <- ggplot(data, aes_string(x=colnames(data)[colnames(data) == input$variable], colnames(data)[length(colnames(data))]))+
geom_bar(stat="identity")
# Display your plot
print(plot)
}
})
}
shinyApp(ui, server)
关于R Shiny : read data file, 让用户选择变量，用 ggplot 作图，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53113065/