问题描述
最近，我尝试学习shinyapp，并尝试为t-test做一个shinyapp：
library(shiny)
shinyUI(fluidPage(
# Application title
titlePanel("t test shinyapp"),# Sidebar set
sidebarLayout(
sidebarPanel(
h4(fileInput("file","Upload the file"),helpText("Default max. file size is 5MB"),# Horizontal line ----
tags$hr(),uIoUtput("vx1"),br(),uIoUtput("vx2"),uIoUtput("gg"),selectInput("method","Select t test type",c("One-sample t test","Independent two-sample t test","Paired sample t test"),selected = "Independent two-sample t test"),selectInput("alt","Select alternative",c("two.sided","greater","less"),selected = "two.sided"),textInput("mu","Enter population mean for one-sample t test",""),radioButtons("ptype","Select the file type",choices = list("png","pdf")))),mainPanel(
uIoUtput("tb")
)
)))
shinyServer(function(input,output) {
dff <- reactive({
file1 <- input$file
if(is.null(file1)){return()}
read.csv(file=file1$datapath,header = TRUE)
})
output$vx1 <- renderUI({
selectInput("var1","Select variable names",choices = names(dff()))
})
output$vx2 <- renderUI({
selectInput("var2",choices = names(dff()))
})
output$gg <- renderUI({
selectInput("gro","Select group name",choices = names(dff()))
})
output$sum <- renderTable({
if(is.null(dff())){return ()}
print(c(paste0("You choice to do: ",input$method),paste0("The way you use to test is: ",input$alt),paste0("The variable you choice is: ",input$var1),paste0("The group variable you selected is: ",input$gro),paste0("the levels of group variable is:",levels(as.factor(dff()[input$gro])))),sep = "\n")
print(dff()[input$gro])
})
output$tr <- renderTable({
if(is.null(dff())){return ()}
if(input$method == "One-sample t test"){
t.test(dff1[input$var1],mu = as.numeric(input$mu),alternative = input$alt)
} else if(input$method == "Independent two-sample t test"){
t.test(input$var1 ~ input$gro,data = dff(),alternative = input$alt)
}else{
t.test(dff()[input$var1],dff()[input$var2],paired=TRUE,alternative = input$alt)
}
})
output$tplot <- renderPlot({
})
downloadHandler(
filename = function(){
paste(input$method,input$ptype,sep = ".")
},content = function(){
if(input$ptype == "png")
png(file)
else
pdf(file)
dev.off()
}
)
output$tb <- renderUI({
if(is.null(data()))
h5("Powered by",tags$img(src='qrcode.jpg'))
else
tabsetPanel(tabPanel("Summary",tableOutput("sum")),tabPanel("t test result",tableOutput("tr")),tabPanel("Plot",downloadButton("download","download the plot"),))
})
})
如您所见，我可以在 output$sum 中打印 dff()[input$gro]，但无法在 output$tr 中运行。
当我运行代码时，出现错误：t.test.formula 中的错误：分组因子必须恰好有 2 个级别。
有什么问题。非常感谢。
解决方法
您可以尝试将 output$tr 代码更改为：
output$tr <- renderTable({
if(is.null(dff())){return ()}
if(input$method == "One-sample t test"){
t.test(dff1[[input$var1]],mu = as.numeric(input$mu),alternative = input$alt)
} else if(input$method == "Independent two-sample t test"){
t.test(reformulate(input$gro,input$var1),data = dff(),alternative = input$alt)
}else{
t.test(dff()[[input$var1]],dff()[[input$var2]],paired=TRUE,alternative = input$alt)
}
})