rplotopenair

Need the word Delta spelled out in an R plot title but keeps converting to delta symbol


I'm making a plot of air quality in Delta Junction, Alaska and am trying to add a title to my figure that says "Delta Junction Air Quality Index" but the Delta part of the title gets converted to the delta symbol and I can't figure out how to keep it from doing that.

I'm using the openair package to create this plot. My example code below also uses lubridate to create a date column of the airquality built in dataset.

I first tried just using main = "Delta Junction Air Quality Index"

library(lubridate)
library(openair)
test <- as.data.frame(airquality)
test$date <- NA
test$date <- paste(test$Month,"-",test$Day,"- 2024")
test$date <- mdy(test$date)
calendarPlot(test, 
             pollutant = "Ozone",
             month = 5,
             statistic = "mean", 
             annotate = "value",
             main = "Delta Junction Air Quality Index")

This is what the resulting plot looked like:

Figure 1

I also tried specifying a title as its own object, to no avail.

title <- "Delta Junction Air Quality Index"
test <- as.data.frame(airquality)
test$date <- NA
test$date <- paste(test$Month,"-",test$Day,"- 2024")
test$date <- mdy(test$date)
calendarPlot(test, 
             pollutant = "Ozone",
             month = 5,
             statistic = "mean", 
             annotate = "value",
             main = title)

I then tried the below code which did keep Delta spelled out but added asterisks * around the word:

test <- as.data.frame(airquality)
test$date <- NA
test$date <- paste(test$Month,"-",test$Day,"- 2024")
test$date <- mdy(test$date)
calendarPlot(test, 
             pollutant = "Ozone",
             month = 5,
             statistic = "mean", 
             annotate = "value",
             main = "'Delta' Junction Air Quality Index")

Figure 2


Solution

  • Use auto.text= FALSE: from ?calendarPlot,

    auto.text: Either ‘TRUE’ (default) or ‘FALSE’. If ‘TRUE’ titles and axis labels will automatically try and format pollutant names and units properly e.g. by subscripting the `2' in NO2.

    (It would be harder if you want to protect "Delta" from translation and convert subscripts etc. automatically ... you could probably provide the title as an expression as in ?plotmath ...)