How to remove/change the label in a plotly geom_vline in R?

Question

Using this example from plotly I am attempting to plot two vertical lines to represent the mean and median.

Reproducible Code

library(plotly)

# data
df1 <- data.frame(cond = factor( rep(c("A","B"), each=200) ),
                  rating = c(rnorm(200),rnorm(200, mean=.8)))

df2 <- data.frame(x=c(.5,1),cond=factor(c("A","B")))

# graph
ggplot(data=df1, aes(x=rating, fill=cond)) +
  geom_vline(aes(xintercept=mean(rating, na.rm=T))
             , color="red", linetype="dashed", size=1, name="average") +
  geom_vline(aes(xintercept=median(rating, na.rm=T))
             , color="blue", linetype="dashed", size=1, name="median") +
  geom_histogram(binwidth=.5, position="dodge")

ggplotly()

Problem

I want to suppress the y-value -2.2 that is displayed next to the red text 'average'. However, I want the text 'average' to display as it does in the screenshot below. I.e. I only want to suppress the label that I have put a black cross through. The same problem applies to the median line.

My non-working attempt

#plot
gg <- ggplot(data=df1, aes(x=rating, fill=cond)) +
    geom_vline(aes(xintercept=mean(rating, na.rm=T))
               , color="red", linetype="dashed", size=1, name="average")+
    geom_vline(aes(xintercept=median(rating, na.rm=T))
               , color="blue", linetype="dashed", size=1, name="median") +
    geom_histogram(binwidth=.5, position="dodge")

p <- plotly_build(gg)
# p$data[[1]]$y[1:2] <- " " # another attempt, but the line doesn't display at all
p$data[[1]]$y <- NULL # delete the y-values assigned to the average line
plotly_build(p)

This attempt still displays a 0 (screenshot below):

Answer 1

Solution

#plot
gg <- ggplot(data=df1, aes(x=rating, fill=cond)) +
    geom_vline(aes(xintercept=mean(rating, na.rm=T))
               , color="red", linetype="dashed", size=1, name="average")+
    geom_vline(aes(xintercept=median(rating, na.rm=T))
               , color="blue", linetype="dashed", size=1, name="median", yaxt="n") +
    geom_histogram(binwidth=.5, position="dodge")

#create plotly object
p <- plotly_build(gg)

#append additional options to plot object
p$data[[1]]$hoverinfo <- "name+x" #hover options for 'average'
p$data[[2]]$hoverinfo <- "name+x" #hover options for 'median'

#display plot
plotly_build(p)

Result (screenshot)

Explainer

The object p is a list of plotly options, but does not include all options. It appears the R API to plotly implicitly uses all the defaults. Therefore, if you want something different you need to append the option name (e.g. hoverinfo) with the custom settings (e.g. "name+x").

Plotly reference material