Additional variable in hover tooltips

[royfrancis]

How can we show additional variables in tooltips? Say I have a dataframe with x,y and z. df <- data.frame(x=c(4,5,6,3),y=c(2,4,3,2),z=c("A","A","A","B")) x and y are on x and y axis respectively. z is not used in anyway for plotting. Not even as grouping variable. How do I show z variable in the tooltip?

[jbkunst]

Hi @royfrancis !

This package is a really straight forward wrapper for highcharts. So we need to construct the data as highcharts need. So it is really useful if you study the api via examples. In particular lets see http://www.highcharts.com/demo/bubble, and click View options then look how is the data and you'll see:

   series: [{
            data: [
                { x: 95, y: 95, z: 13.8, name: 'BE', country: 'Belgium' },
                { x: 86.5, y: 102.9, z: 14.7, name: 'DE', country: 'Germany' },
                ....

To add this type of data to highcarts via highcarter we need to parse the data frame using list.parse (basically put a dataframe in a list form) function from rlist package (I change the z name colum because if the type of chart is bubble this value will be used to get the bubble's size:

So internally we'll have something like:

   series: [{
            data: [
                { x: 4, y: 2, text: 'A'},
                { x: 5, y: 4, text: 'A'},
                ....

Well TLDR. Here's the code.

library("highcharter")
library("rlist")

df <- data.frame(
  x=c(4,5,6,3),
  y=c(2,4,3,2),
  text=c("A","A","A","B"), stringsAsFactors = FALSE)

# ds: data series
ds <- list.parse(df)
names(ds) <- NULL

head(ds)

highchart() %>% 
  hc_add_serie(data = ds, name = "data.frame data",
               type = "scatter") %>% 
  hc_tooltip(headerFormat = "<b>This is a custom tooltip</b><br>",
             pointFormat = "x: {point.x} <br> y: {point.y} <br> text: {point.text}")