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[英]How do I display variable number of ggplots in R shiny, depending on input?
[英]How do I display text output in Shiny depending on the result of a caluclation?
我正在使用 Shiny 並有三個目標:
a) 用戶可以從下拉菜單中選擇 select 變量
b) 計算 Cramer's V 並將結果顯示在屏幕上
c) 根據結果,顯示特定文本 output,例如“這是一個強關聯”
我已經成功地完成了目標 a 和 b。 我在目標三上嘗試了各種嘗試,但都無濟於事。
下面的這段代碼顯示了兩種不起作用的嘗試:
library(shinydashboard)
library(shiny)
library(dplyr)
library(DT)
library(rcompanion)
df <- data.frame(ACCIDENT_MASTER_single)
Cat1.Variables <- c("SEVERITY", "ATMOSPH_COND", "DAY_OF_WEEK", "CAT")
Cat2.Variables <- c("SEVERITY", "ATMOSPH_COND", "DAY_OF_WEEK", "CAT")
ui <- fluidPage(
titlePanel("Calculate the strength of the relationship between categorical variables"),
sidebarLayout(
sidebarPanel(
selectInput("cat1", choices = Cat1.Variables, label = "Select a Categorical Variable:"),
selectInput("cat2", choices = Cat2.Variables, label = "Select a Categorical Variable:")
),
mainPanel(
textOutput("text1"),
h3(tableOutput("results")),
textOutput("text2")
)
)
)
server <- shinyServer(function(input, output) {
cramerdata <- reactive({
req(input$cat1, input$cat2)
df3 <- data.matrix(ACCIDENT_MASTER_single[c(input$cat1, input$cat2)])
df3
})
results <- reactive({
cramerV(cramerdata())
})
output$text1 <- renderText({
paste("You have selected variables:", input$cat1, input$cat2)
})
output$results <- renderPrint({
cat(sprintf("\nThe results equal: \n"))
x <- cramerV(cramerdata())
print(x)
if (x >.5) {
return(paste("<span style=\"color:red\">There is a strong association between the selected variables </span>"))
} else if
(x > 0.3 && x <= 0.5) {
"There is a medium association between the selected variables"
} else if
(x > 0.1 && x <= 0.3) {
"There is a weak association between the selected variables"
} else
"There is a very weak association between the selected variables"
})
output$text2 <- renderText({
if (x >.5) {
return(paste("<span style=\"color:red\">There is a strong association between the selected variables </span>"))
} else if
(x > 0.3 && x <= 0.5) {
"There is a medium association between the selected variables"
} else if
(x > 0.1 && x <= 0.3) {
"There is a weak association between the selected variables"
} else
"There is a very weak association between the selected variables"
})
})
shinyApp(ui, server)
我在 output$results 下得到的 output 如下:
結果相等:Cramer V 0.605 [1]“所選變量之間存在強關聯”
我了解 output 與 [1] 和“”看起來像這樣,因為我使用的是 renderPrint。 但是,當我使用 renderText 時,我得到文本 output 產生正確的 output 但根本不顯示 Cramer's V 的結果(目標 b)。
您可以在我的代碼中看到我還嘗試將文本 output 分別放在 output$text2 下,但它會產生以下結果:
錯誤:未找到 object 'x'。
任何人都可以幫助解決這個問題嗎?
謝謝
您的第二次嘗試不起作用,因為變量 'x' 不是全局變量,它在output$results
下定義,您無法在output$text2
中訪問它。 我無法運行您的整個代碼,因為您沒有提供必要的數據,但我想這會為您完成這項工作:
# in the ui change your tableOutput() to textOutput() for 'results':
h3(textOutput("results"))
# in the server change your output$results to this:
output$results <- renderText({
x <- cramerV(cramerdata())
print(paste("The results equal:", x, ifelse(x > 0.5, "There is a strong association between the selected variables",
ifelse(x > 0.3 && x <= 0.5, "There is a medium association between the selected variables",
ifelse(x > 0.1 && x <= 0.3, "There is a weak association between the selected variables", "There is a very weak association between the selected variables")))))
})
PS您已經將cramerV(cramerdata())
放在results()
反應元素中,那么為什么要在output$results
中重寫它。
PSS:盡量不要為變量和函數使用相同的名稱(就像這里的results
一樣作為反應元素和輸出)
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