Interactive data point selection with ggplotly/plotly charts

eventdata.R

## Load required packages

library(plotly)
library(ggplot2)
library(shiny)

## Defining a key column in mtcars which will be used for event handling in event_data()
mtcars$key <- row.names(mtcars)


### Ui code begins below
ui <- fluidPage(
  h1("Demo - Interactive data point selection with ggplotly/plotly charts"),
  h4("Subset the dataset using the data points selected from the chart. Drag and select one or multi data points"),
  br(),
  ## Plotly plot display
  plotlyOutput("plot"),
  
  ## Data point information display post click
  verbatimTextOutput("click")
)


## Server side code begins below
server <- function(input, output, session) {
  
  ## ggplotly scatter plot
  output$plot <- renderPlotly({
    
    myplot <- ggplot(mtcars, aes(x = mpg, 
                            y = wt, 
                            key = key)) + geom_point()
    ## in above code line, use the argument key inside ggplot which will be used for event handling
    ggplotly(myplot) %>% 
      layout(dragmode = "select")
    
  })
  
  ## returns the data related to data points selected by the user
  output$click <- renderPrint({

    
    ## Click_data will have the keys (row identifiers) corresponding to selected data points
    click_data <- event_data("plotly_selected")

    ## Event mode options. There are many more to experiment
    ## plotly_click - click on one data point
    ##  Plotly_selected - multi point select
        
    if(is.null(click_data)) 
      "No data points selected on scatter plot..." 
    else 
      filter(mtcars, key %in% click_data$key) %>% select(-key)
    ## Subsetting in above step based on selected data points and removing the key column
    
  })
}
shinyApp(ui, server)

Do yo know why the data.frame returned by event_data() only accepts a new "key" column, but no columns with other names? I tried using "id" instead of "key", and struggled a lot to realize that the problem behind the new variable not being added to the data.frame was that column name restriction.

Hello,
event_data return a key argument. That can't be changed, however you should be able to define whatever that key should should be from your data frame. Are you saying you encountered errors when you defined some other column name in the ggplot( .... key = "someothername")?

I didn't know key was an argument. I thought it was just a variable you were creating inside aes() that would be fetched by event_data. Similar to adding variables in aes() to be displayed in the tooltip of plotly.
Thanks for clarifying!

Sure, thanks. Happy to help. ty Abi.

Hello,
Thanks for sharing this useful scripts.
Now I can use your scripts to select points and copy the key from the window and paste to variable later. But I've a minor question which is how can i output the key into an R environment variable directly? So that I can use downstream scripts for those selected points.
I tried adding a line below line 54 savekey <- click_data$key ,but after running it the savekey doesn't appear in variables.
Do you have any suggestions? Thanks in advance! @aagarw30

Hello, so you just need to catch and use the value of key? Ty Abi

…

On Mon, 10 Jul 2023 at 6:59 AM, ZYLI ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ Hello, Thanks for sharing this useful scripts. Now I can use your scripts to select points and copy the key from the window and paste to variable later. But I've a minor question which is how can i output the key into an R environment variable directly? So that I can use downstream scripts for those selected points. I tried adding a line below line 54 savekey <- click_data$key ,but after running it the savekey doesn't appear in variables. Do you have any suggestions? Thanks in advance! @aagarw30 <https://github.com/aagarw30> — Reply to this email directly, view it on GitHub <https://gist.github.com/aagarw30/1a86725add60b9dae42fbb44b8e94817#gistcomment-4621867> or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABXF2WYVXBV2UVB3DE3BFWTXPNLGLBFKMF2HI4TJMJ2XIZLTSGBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVEYTAMRRGE3DKMZZU52HE2LHM5SXFJTVOBSGC5DF> . You are receiving this email because you were mentioned. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .

Yes, I need to catch the key and use the key to subset points from the whole points.

Ok, will work on it today and update . Thank you!

…

On Mon, 10 Jul 2023 at 10:53 AM, ZYLI ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ Yes, I need to catch the key and use the key to subset points from the whole points. — Reply to this email directly, view it on GitHub <https://gist.github.com/aagarw30/1a86725add60b9dae42fbb44b8e94817#gistcomment-4623981> or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABXF2W2YCU7RLQX4XIF6MITXPOGURBFKMF2HI4TJMJ2XIZLTSKBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFQKSXMYLMOVS2I5DSOVS2I3TBNVS3W5DIOJSWCZC7OBQXE5DJMNUXAYLOORPWCY3UNF3GS5DZVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVEYTAMRRGE3DKMZZU52HE2LHM5SXFJTDOJSWC5DF> . You are receiving this email because you authored the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .

Hello, I figured out a way and forked your gist.
Thank you!

Good news! Ty Abi.

…

On Tue, 11 Jul 2023 at 1:31 PM, ZYLI ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ Hello, I figured out a way and forked your gist. Thank you! — Reply to this email directly, view it on GitHub <https://gist.github.com/aagarw30/1a86725add60b9dae42fbb44b8e94817#gistcomment-4625277> or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABXF2W3INNAOBSZ4LBD7R6TXPUB6DBFKMF2HI4TJMJ2XIZLTSKBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFQKSXMYLMOVS2I5DSOVS2I3TBNVS3W5DIOJSWCZC7OBQXE5DJMNUXAYLOORPWCY3UNF3GS5DZVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVEYTAMRRGE3DKMZZU52HE2LHM5SXFJTDOJSWC5DF> . You are receiving this email because you authored the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .