用ggvis在交互式层下面添加层

Question

I want to use the tooltip function within ggvis to create hover text for specific points along a curve. I can get the plot to form, but the text in the hover field won't show up. This occurs when I try to add a background layer that should not be considered part of the interactive part of the visualization. Below is some code illustrating:

library(ggvis)
# one-compartment oral concentration curve
comp1.oral <- function(ka,ke,v,f,dose,time){
  (ka * dose * f)/ (v*(ka-ke)) * (exp(-ke * time) - exp(-ka*time))
}

time <- 0:200 # time points to create curve
tp <- 6  # number of times to sample
tmax <- max(time) 
#generically choosing tp points to sample at
tnew <- exp(seq(0,log(tmax),length=(tp)))
#computing the concentration (y value)
y <- comp1.oral(.1,.03,4,1,100,tnew)            

#creating dataframe with values
# PK and ECG should be in the hover text
d1 <- data.frame(
  Conc= y,
  Time=tnew,
  PK = 1:tp,
  ECG= "No"
    )
# creating a column with the text to appear in the hover box
d1$long <- paste0("PK: ",d1$PK,"<br>","ECG: ",d1$ECG,"<br>")

#creating another data frame to input the time-conc curve as a background layer
d2 <- data.frame(
  x=time,
  y=comp1.oral(.1,.03,4,1,100,time)
  )

The code below will form the plot I want but without the hover text.

d1 %>% 
  ggvis(x = ~Time, y=~Conc) %>%
  layer_points(size.hover:=200) %>% 
  layer_paths(~x,~y,data=d2) %>%
  add_tooltip(function(d1){
    if (!is.null(d1$Time)) paste0("PK:", "<br>ECG:", "<br>Time: ", as.character(round(d1$Time)), " minutes post-dose")
  }, "hover")

I would like to get the otehr values from d1$long into the hover text box. I tried adding it similar to what is seen in the rotten tomatoes shiny example, but it wouldn't work.

I tried the following, but it can't seem to find the additional text in the variable d1$long

d1 %>% 
  ggvis(x = ~Time, y=~Conc, key := ~long) %>%
  layer_points(size.hover:=200) %>% 
  layer_paths(~x,~y,data=d2) %>%
  add_tooltip(function(d1){
    if (!is.null(d1$Time)) paste0(as.character(d1$long),"Time: ", as.character(round(d1$Time)), " minutes post-dose")
  }, "hover")

Answer 1

The error is that the variable should be passed in the layer_points

d1 %>% 
  ggvis(x = ~Time, y=~Conc) %>%
  layer_points(size.hover:=200, key := ~long) %>% 
  layer_paths(~x,~y,data=d2) %>%
  add_tooltip(function(d1){
    if (!is.null(d1$Time)) paste0(as.character(d1$long),"Time: ", as.character(round(d1$Time)), " minutes post-dose")
  }, "hover")