plot vline graph highcharts in r

Question

I need to plot a vertical line on a graph, and write the texts "PRE" and "POS" as shown in the attached figure, using the package and highcharts. So far I have not been successful. Follow my code so far.

hc <- bd
  
  plotline <- list(color ="red", value =2015.5, width =5)

  hchart('line', hcaes(x = hc$ANO, y = hc$Percentual, group = Niveis)%>%
  hc_yAxis(plotLines = list(plotline)) 
   
) 

hc

Answer 1

You didn't provide data, so I grabbed some to use. I didn't try to match styles or colors - you didn't indicate that was a need.

library(tidyverse)
library(highcharter)
library(lubridate)

weather # from highcharter package
w2 = weather %>% pivot_longer(min_temperaturec:mean_temperaturec, names_to = "Niveis", values_to = "Percentual")

hchart(w2, 'line', hcaes(x = date, 
                         y = Percentual, 
                         group = Niveis)) %>%  
  hc_xAxis(plotLines = list(list(value = datetime_to_timestamp(median(w2$date)),  # I used the median date
                                                                                  # any 'date' you use needs the function
                                                                                  # datetime_to_timestamp()
                                    width = 5, color = "red"))) %>% 
  # add Z index to put on top zIndex = 5
  hc_annotations(list(
    labels = 
      list(
        list(
          point = list(x = datetime_to_timestamp(min(w2$date)),       # using the minimum date
                       y = max(w2$Percentual), xAxis = 0, yAxis = 0), # using the maximum y value
          text = "PRE"
        ),
        list(
          point = list(x = datetime_to_timestamp(max(w2$date)),       # using the maximum date
                       y = max(w2$Percentual), xAxis = 0, yAxis = 0), # using the maximum y value
          text = "POST"
        ))))