Multiple y-axes in shiny app w/ highcharter - r

Question

I'm trying to render a graph in a shiny app using highcharter that shares an x-axis (days) but has multiple y-axes (a percent and a count). After some research it seems like I should use the 'hc_yAxis_multiples' method. On the left y-axis, I have % displayed. On the right y-axis, I want the count displayed. There is a line graph that is based on the left y-axis (%), and a stacked bar graph that is displayed based on the right y-axis.
I have been able to overlay the two graphs, but the bar chart portion based on the right y-axis is not formatted to the corresponding y-axis. Based on what I have been looking at, it seems like something like this would produce a result that I want:
##This first block is to show what the data types of the variables I'm using are and what the structure of my df looks like
df$inbox_rate <- df$total_inbox / df$total_volume
df$inbox_rate <- round((df$inbox_rate*100),0)
df$received_dt <- as.character(df$received_dt)
df$received_dt <- as.Date(df$received_dt, "%Y%m%d")
df <- df[order(df$received_dt),]
## This second block here is where I'm trying to build the chart with two Y-axes
hc <- highchart()%>%
hc_title(text = paste(domain_name,sep=""),align = "center") %>%
hc_legend(align = "center") %>%
hc_xAxis(type = "datetime", labels = list(format = '{value:%m/%d}')) %>%
hc_yAxis_multiples(list(title = list(text = "IPR"),labels=list(format = '{value}%'),min=0,
max=100,showFirstLabel = TRUE,showLastLabel=TRUE,opposite = FALSE),
list(title = list(text = "Total Subscribers"),min=0,max = max(df$total_users),
labels = list(format = "{value}"),showLastLabel = FALSE, opposite = TRUE)) %>%
hc_plotOptions(column = list(stacking = "normal")) %>%
hc_add_series(df,"column",hcaes(
x=received_dt,y=total_users,group=isp,yAxis=total_users)) %>%
hc_add_series(df,type="line",hcaes(
x=received_dt,y=inbox_rate,group=isp,yAxis=inbox_rate)) %>%
hc_exporting(enabled = TRUE) %>%
hc_add_theme(thm)
hc
However this produces something that looks like this.
To give more insight about the data I'm using, the domain_name is a string variable that looks like this: example.com. The total_users variable is a number that varies from 0 to about 50000. The received_dt variable is a date, formatted using as.Date(df$received_dt, "%Y%m%d"). The inbox_rate variable is a percent, from 0 to 100.
The bar counts are all displaying to the full height of the graph, even though the values of the bars vary widely. To reiterate, I want the right y-axis that the bar chart heights are based on to be the count of the df$total_users. Within the hc_yAxis_multiples function, there are two lists given. I thought that the first list gives the left y-axis, and the second gives the right. The closest answer to my question that I could find was given by this stackoverflow response
If anyone has any insight, it would be very much appreciated!

Answer 1

Your use of the yAxis statement in hc_add_series seems to be off. First, it should not be inside hcaes and second, it's a number specifying which axis (in order of appearance in hy_yAxis_multiple call) the series belongs to. So hc_add_series(..., yAxis = 1) should be used to assign a series to the second (right) axis.
Below is a (fully self-explaining, independent, minimal) example that shows how it should work.
library(highcharter)
df <- data.frame(
total_inbox = c(2, 3, 4, 5, 6),
total_volume = c(30, 30, 30, 30, 30),
total_users = c(300, 400, 20, 340, 330),
received_dt = c("20180202", "20180204", "20180206", "20180210", "20180212"),
isp = "ProviderXY"
)
df$inbox_rate <- df$total_inbox / df$total_volume
df$inbox_rate <- round((df$inbox_rate*100),0)
df$received_dt <- as.character(df$received_dt)
df$received_dt <- as.Date(df$received_dt, "%Y%m%d")
df <- df[order(df$received_dt),]
hc <- highchart()%>%
hc_xAxis(type = "datetime", labels = list(format = '{value:%m/%d}')) %>%
hc_yAxis_multiples(list(title = list(text = "IPR"),labels=list(format = '{value}%'),min=0,
max=100,showFirstLabel = TRUE,showLastLabel=TRUE,opposite = FALSE),
list(title = list(text = "Total Subscribers"),min=0,max = max(df$total_users),
labels = list(format = "{value}"),showLastLabel = FALSE, opposite = TRUE)) %>%
hc_plotOptions(column = list(stacking = "normal")) %>%
hc_add_series(df,type="column",hcaes(x=received_dt,y=total_users,group=isp),yAxis=1) %>%
hc_add_series(df,type="line",hcaes(x=received_dt,y=inbox_rate,group=isp))
hc
Maybe take this as an example how code in questions should be like. Copy-Paste-Runnable, no outside variables and minus all the things that dont matter here (like the theme and legend for example).