r - How to choose variable to display in tooltip when using ggplotly?

Question

I have a simple data frame:

seq <- 1:10
name <- c(paste0("company",1:10))
value <- c(250,125,50,40,40,30,20,20,10,10)
d <- data.frame(seq,name,value)

And I want to plot it this way:

require(ggplot2)
ggplot(data = d,aes(x=seq,y=value))+geom_line() + geom_point()

Now I want to use plotly, mostly to be able, when mousing over a point, to get other information than the value, such as the company name. I try this :

require(plotly)
ggplotly()

which get me a tooltip, but with only seq and value. I tried the option tooltip= but it's specified you can use the only variable describe in the aesthetic, and I don't use the name in my aes.

Any solution? I saw I am not the first with this problem, but I haven't found answer working with ggplotly.

Answer 1

You don't need to modify the plotly object as suggested by @royr2. Just add label = name as third aesthetic

ggplot(data = d, aes(x = seq, y = value, label = name)) + geom_line() + geom_point()

and the tooltip will display name in addition to seq and value.

The ggplotly help file says about tooltip parameter:

The default, "all", means show all the aesthetic mappings (including the unofficial "text" aesthetic).

So you can use the label aesthetic as long as you don't want to use it for geom_text.

BTW: I've also tried text instead of label

ggplot(data = d, aes(x = seq, y = value, text = name)) + geom_line() + geom_point()

but then ggplot2 complained

geom_path: Each group consists of only one observation. Do you need to adjust the group aesthetic?

and plotted only points. I had to add a dummy group to geom_line to remove the issue:

ggplot(data = d, aes(x = seq, y = value, text = name)) + geom_line(group = 1) + geom_point()

(But note if you put the dummy group as fourth aesthetic inside aes() it will appear by default also in the tooltip.)

However, I find the unofficial text aesthetic can become useful alongside label if you want to have different strings plotted by geom_text and shown in the tooltip.

Edit to answer a question in comments: The tooltip parameter to ggplotly() can be used to control the appearance. ggplotly(tooltip = NULL) will suppress tooltips at all. ggplotly(tooltip = c("label")) selects the aesthetics to include in the tooltip.