Convert English numbers to Persian numbers for ggplot

Question

I am working on a data visualization project using ggplot2.

All numbers obtained in the plot (Includes axis-x and axis-y and numbers inside the plot) are in English format like the below plot:

but I want the numbers in all plots to be Persian (e.g., ۲۰۱۵ instead of 2015).

I have many plots with different numbers. Can anyone help me to convert English numbers in the plot to Persian?

Answer 1

Approach 1 - replacing numbers

I found this function you wrote in the other question:

convert_english_to_farsi <- function(x) {
  persian <- "\u0660\u0661\u0662\u0663\u0664\u0665\u0666\u0667\u0668\u0669\u06F0\u06F1\u06F2\u06F3\u06F4\u06F5\u06F6\u06F7\u06F8\u06F9"
  english <- "\U0030\U0031\U0032\U0033\U0034\U0035\U0036\U0037\U0038\U0039\U0030\U0031\U0032\U0033\U0034\U0035\U0036\U0037\U0038\U0039"
  return(chartr(english, persian, x))
}

This actually works quite well for me (I checked here):

convert_english_to_farsi(123456)
#> [1] "۱۲۳۴۵۶"

You can just use this function as the labels argument in most scale_* functions in ggplot2. For example if we want to change the y-axis labels of some plot (economics is included in ggplot2 so this is reproducible):

library(ggplot2)
ggplot(economics, aes(x = date, y = unemploy)) +
  geom_line() +
  scale_y_continuous(labels = convert_english_to_farsi)

The highest number here is supposed to be 12,000 which translates to ۱۲۰۰۰, which looks correct.

^{Created on 2021-02-07 by the reprex package (v1.0.0)}

Approach 2 - replacing the font

Alternativly, you can use a different font that uses Persian numbers. I found one here. Download and install it in Windows. Then load it using the extrafont package:

library(extrafont)
#> Registering fonts with R
font_import(
  path = "~/Fonts", # I placed only the downloaded ttf file here so only the relevant font is imported
  recursive = FALSE
)

You can check available fonts with:

fonts()
#> [1] "Persian Pager Number"

Now change the font in your ggplot2 theme like this:

ggplot(economics, aes(x = date, y = unemploy)) +
  geom_line() +
  theme_minimal(base_family = "Persian Pager Number")