r - 使用 Shiny Inputs 在数据集中创建新变量

Question

假设我们有一个小的 nfl 球员数据集:

      Team  POS  WT
1    Chiefs   K 175
2     Bills   K 225
3    Browns  CB 175
4  Chargers  DT 300
5    Browns  TE 220
6    Texans  LB 262
7   Cowboys  LB 234
8  Patriots  DT 309
9    Titans   K 218
10   Browns  WR 167

我想创建一个 Shiny 的页面，让人们将自己的权重 (WT) 放入其中，并且在数据集中，它将创建每个 nfl 球员的权重与输入权重之间的差异。

到目前为止....不。

ui.R

shinyUI(fluidPage(


titlePanel(h1("Which NFL Player Are You Most Like?", align = "center")),


sidebarLayout(
 sidebarPanel(

  selectInput("team", "Choose a Team:", 
              choices = c("All","49ers","Bears","Bengals", "Bills", 
                          "Broncos","Browns","Buccaneers", "Cardinals",
                          "Charges","Cheifs","Colts", "Cowboys",
                          "Dolphins","Eagles","Falcons", "Giants",
                          "Jaguars","Jets","Lions", "Packers",
                          "Panthers","Patriots","Raiders", "Rams",
                          "Ravens","Redskins","Saints", "Seahawks",
                          "Steelers","Texans","Titans", "Vikings")),



  selectInput("Position", "What is your Football Position?:", 
              choices = c("All","C",  "CB", "DE", "DT", "FB", "G",  "K",  "LB", "LS", "NT", "P",  "QB", "RB",
                          "S",  "T",  "TE", "WR")),

  numericInput("Weight", "How Much Do You Weigh? (LBS):", NA)


),

mainPanel(
  p("Use the panel at the right to input your own information. Below will be the name or names of players you are most like. If you only want to use
    a subset of variables, leave the others blank or set to 'All'."),

#Right now I just want to know that it worked, so show me the updated dataset where there is   the Weight_diff column
  tableOutput("view")

  )
 )
))

server.R

library(shiny)
 NFLdat<-structure(list(Team = structure(c(10L, 4L, 6L, 9L, 6L, 30L, 12L, 
                              22L, 31L, 6L), .Label = c("49ers", "Bears", "Bengals", "Bills", 
                                                        "Broncos", "Browns", "Buccaneers", "Cardinals", "Chargers", "Chiefs", 
                                                        "Colts", "Cowboys", "Dolphins", "Eagles", "Falcons", "Giants", 
                                                        "Jaguars", "Jets", "Lions", "Packers", "Panthers", "Patriots", 
                                                        "Raiders", "Rams", "Ravens", "Redskins", "Saints", "Seahawks", 
                                                        "Steelers", "Texans", "Titans", "Vikings"), class = "factor"), 
           POS = structure(c(7L, 7L, 2L, 4L, 16L, 8L, 8L, 4L, 7L, 17L
           ), .Label = c("C", "CB", "DE", "DT", "FB", "G", "K", "LB", 
                         "LS", "NT", "P", "QB", "RB", "S", "T", "TE", "WR"), class = "factor"), 
           WT = c(175L, 225L, 175L, 300L, 220L, 262L, 234L, 309L, 218L, 
                  167L)), .Names = c("Team", "POS", "WT"), row.names = c(NA, 
                                                                         10L), class = "data.frame")

shinyServer(function(input, output) {



observe({
 if(is.na(input$Weight)) NFLdat$Weight_diff<-abs(data$WT-data$WT)
 else NFLdat$Weight_diff<-abs(data$WT-((as.numeric(input$Weight))))
})


#Or alternatively
 inputWT <- reactive({
  input$Weight
 })

NFLdat$Weight_diff2<-abs(data$WT-inputWT)

output$view <- renderTable({
 NFLdat
}) 



output$new <-inputWT
})

谢谢!!!

Answer 1

您可能想要创建一个响应式表达式，该表达式返回准备好呈现的 NFLdat 子集。我猜你的 shinyServer 应该是这样的:

 shinyServer(function(input, output) {

 NFLdat.2show <- reactive({
     #browser()
     if (is.na(input$Weight)) return()

     bmask.team <- if (input$team!='All') NFLdat$Team==input$team else TRUE
     d <- NFLdat[bmask.team,]
     d$Weight_diff <- abs(d$WT-input$Weight)

     d
 })  

 output$view <- renderTable({
     NFLdat.2show()
 })

 })