Add info to the info box of a dygraph with the relevant R package

Question

#libraries
library(data.table)
library(dygraphs)
library(xts)

#dummy data
dates <- data.table(dates  = seq.Date(as.Date("2017-03-01"), length = 14, by = "month"),
                    satisfaction = runif(14, min = 0.1, max = 1),
                    answers = runif(14, min = 100, max = 1000),
                    )

#convert to xts
xts_dates <- xts(dates, order.by = as.POSIXct(dates$dates, format = ("%Y-%m-%d")))
dygraph(xts_dates)

I want only to plot satisfaction and add the answers data either to the info box on the top right corner or elsewhere where it's visible

Answer 1

#libraries
library(data.table)
library(dygraphs)
library(xts)

#dummy data
dates <- data.table(dates  = seq.Date(as.Date("2017-03-01"), length = 14, by = "month"),
                    satisfaction = runif(14, min = 0.1, max = 1),
                    answers = runif(14, min = 100, max = 1000)
                    )

#convert to xts
xts_dates <- xts(dates, order.by = as.POSIXct(dates$dates, format = ("%Y-%m-%d")))
xts_dates <- xts_dates[, 2:3]

#create dygraph with double axes
dygraph(xts_dates, main = "Satisfaction") %>%
  dyAxis("y", label = "Satisfaction") %>%
  dyAxis("y2", label = "Number of answers", independentTicks = TRUE) %>%
  dySeries("answers", axis = 'y2')

Basically, I added an additional axis for number of answers.