Exclude line / dots from displaying information when using add_tooltip with hang in ggvis

Question

I played with the beautiful ggvis package. I am doing a custom linear regression and wanted a tooltip to show information about each data point. However, when I add my regression line, a tooltip appears when I hover over the line, and then shows information about the first datapoint (see screenshot). I provide this simple reproducible example:

library(ggvis)
mtc <- mtcars
lm=with(mtc,lm(mpg~wt))
mtc$fit=lm$coefficients[1]+mtcars$wt*lm$coefficients[2]
mtc$id <- 1:nrow(mtc)  # Add an id column to use ask the key

all_values <- function(x) {
    if(is.null(x)) return(NULL)
    row <- mtc[mtc$id == x$id, ]
    paste0(names(row), ": ", format(row), collapse = "
           ")
}

mtc %>% ggvis(x = ~wt, y = ~mpg, key := ~id) %>%
    layer_points() %>%layer_lines(x= ~wt,y= ~fit)%>% 
    add_tooltip(all_values, "hover")

It creates

I would like to exclude the regression line from the tooltip so that it only displays information about data points. Is there any way to achieve this? Thanks for the help!

Answer 1

After a short conversation, I made it work.

. mtcars.

mtc <- mtcars
mtc$id <- 1:nrow(mtc) 

lm=with(mtc,lm(mpg~wt))
df=data.frame(fit=lm$coefficients[1]+mtcars$wt*lm$coefficients[2])
df$id <- 101:132
df$wt <- mtcars$wt

, mtc - mtcars, df - . , df id, 100, mtc data.frame.

, all_values, id mtc, , all_values, id df.

, :

all_values <- function(x) {
  #if the id is greater than 100 i.e. the df data.frame
  #then return NULL
  if(x$id>100) return(NULL)
  if(is.null(x)) return(NULL)
  row <- mtc[mtc$id == x$id, ]
  paste0(names(row), ": ", format(row), collapse = "
           ")
}

. add_tooltip id data.frames:

ggvis(x=~wt) %>%
     layer_points(data=mtc, y = ~mpg, key := ~id) %>%
     layer_paths(data=df,y= ~fit, key := ~id) %>%
     add_tooltip(all_values, "hover")

, , , .

.