显示基于rhansontable值的特定列的总和

问题描述

我正在尝试创建一个闪亮的应用程序，当用户选择行时，该应用程序将显示一列的总和(例如mtcars $ mpg).例如，如果在rhandsontable中单击了前两个框，那么在下面我应该看到21和21的总和.我无法绕过它，并且到目前为止已经编写了以下代码:

I am trying to create a shiny app, that would show a sum of a column (say mtcars$mpg) when rows are selected by the users. e.g if the first two boxes are clicked in rhandsontable, then below i should see a sum of 21 and 21. I am unable to wrap my head around it, and have made this code so far:

 library(shiny)
library(rhandsontable)

ui=fluidPage(
  rHandsontableOutput('table'),
  textOutput ('selected')
)

server=function(input,output,session)({

  df <- data.frame(head(transform(mtcars,  Selected = as.logical(NA)  )))

  output$table=renderRHandsontable(
    rhandsontable(df,selectCallback = TRUE,readOnly = FALSE)
  )
  output$selected<-renderText({

  })
}) # end server
shinyApp(ui = ui, server = server)

有什么办法可以做到这一点?

is there any way to achieve this ?

推荐答案

我找到了一种方法！首先将rhansontable保存为r对象，然后再应用子集&聚合函数，然后将结果呈现为表:

I found a way ! saving the rhandsontable as an r object first and then applying subset & aggregate function , then rendering the result as a table :

我可以像这样使用反应式

i can use reactive like this

  tab1 <- reactive({
  if(!is.null(input$table )) {
    nt <- hot_to_r(input$table)
    nt.1<- subset(nt, Selected == TRUE, select = c(mpg,gear))
    nt.2 <- aggregate(nt.1$mpg ~ nt.1$gear , data = nt.1 , FUN = 'sum')  }
  })

:-)

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