使用 R Shiny 进行多元线性回归（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问题，用户可以在其中 select 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的示例，但是对于多个自变量，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 "invalid term in model formula".

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 Whosebug 上的类似帖子似乎表明问题可能出在列名中有空格，但在此示例中并非如此。我不确定如何解决这个问题。谁能帮我指出正确的方向？谢谢！

Answer 1

给你，我喜欢使用 recipe 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，你甚至可以花哨的让用户传递一些 select helpers

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)

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

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