使用 R Shiny 进行多重线性回归 (SelectInput --> multiple=TRUE)

Question

我在让我的 R Shiny 代码生成动态仪表板时遇到了一些麻烦，用户可以在其中选择线性回归模型中的 1 个或多个自变量并打印结果。我已经能够成功地遵循用户只输入一个自变量但有多个自变量的示例，我没有找到同样的运气。我不确定我做错了什么，但我收到一条错误消息，内容为“模型公式中的项无效”。

以下是我目前使用的代码：

library(shinythemes)
library(shinyWidgets)
library(shiny)
library(shinydashboard)


#data(mtcars)

AttributeChoices=c("cyl","disp","hp","drat","wt","qsec","vs")


# Define UI for application
ui = fluidPage(
    navbarPage("R Shiny Dashboard",
        tabPanel("Welcome",
                 tabName = "welcome",
                 icon=icon("door-open"),

          fluidPage(theme=shinytheme("cerulean"),
                    h1("Welcome to my Shiny Dashboard!"),
                    br(),
                    p(strong(tags$u("What is this dashboard all about?"))),
                    p("I'm going to do stuff."),  
                    br(),
                    p(strong(tags$u("Here's another question."))),
                    p("Here's my answer."),
                    br(),
                    p(strong(tags$u("How can I use this dashboard?"))),
                    p("You can click on any of the tabs above to see a different analysis of the data.")
                    )),

              tabPanel("Regression",
                       tabname="regression",
                       icon=icon("calculator"),
                       selectInput(inputId = "indep", label = "Independent Variables", 
                                   multiple = TRUE, choices = as.list(AttributeChoices), selected = AttributeChoices[1]),
                       verbatimTextOutput(outputId = "RegOut")


          )
        ))
# Define server logic 
server <- function(input, output) {

#-------------------REGRESSION-------------------#


  lm_reg <- reactive(
  lm(as.formula(paste(mtcars$mpg," ~ ",paste(input$indep,collapse="+"))),data=CFD)
  )


  output$RegOut = renderPrint({summary(lm_reg())})

}

# Run the application 
shinyApp(ui = ui, server = server)

阅读 StackOverflow 上的类似帖子似乎表明问题可能在于列名包含空格，但在此示例中并非如此。我不知道如何解决这个问题。谁能帮我指出正确的方向？谢谢！

Answer 1

给你，我喜欢使用配方包来解决这样的问题，而不是依赖非常困难的字符串操作，诀窍是使用 !!!运算符，您甚至可以花哨并让用户传递一些选择助手

library(shinythemes)
library(shinyWidgets)
library(shiny)
library(shinydashboard)
library(recipes)
#data(mtcars)

AttributeChoices=c("cyl","disp","hp","drat","wt","qsec","vs")


# Define UI for application
ui = fluidPage(
  navbarPage("R Shiny Dashboard",
             tabPanel("Welcome",
                      tabName = "welcome",
                      icon=icon("door-open"),

                      fluidPage(theme=shinytheme("cerulean"),
                                h1("Welcome to my Shiny Dashboard!"),
                                br(),
                                p(strong(tags$u("What is this dashboard all about?"))),
                                p("I'm going to do stuff."),  
                                br(),
                                p(strong(tags$u("Here's another question."))),
                                p("Here's my answer."),
                                br(),
                                p(strong(tags$u("How can I use this dashboard?"))),
                                p("You can click on any of the tabs above to see a different analysis of the data.")
                      )),

             tabPanel("Regression",
                      tabname="regression",
                      icon=icon("calculator"),
                      selectInput(inputId = "indep", label = "Independent Variables", 
                                  multiple = TRUE, choices = as.list(AttributeChoices), selected = AttributeChoices[1]),
                      verbatimTextOutput(outputId = "RegOut")

             )
  ))
# Define server logic 
server <- function(input, output) {

  #-------------------REGRESSION-------------------#

recipe_formula <- reactive(mtcars %>%
    recipe() %>%
    update_role(mpg,new_role = "outcome") %>%
    update_role(!!!input$indep,new_role = "predictor") %>% 
    formula())

  lm_reg <- reactive(
    lm(recipe_formula(),data = mtcars)
  )


  output$RegOut = renderPrint({summary(lm_reg())})

}

# Run the application 
shinyApp(ui = ui, server = server)