Adding Logo to R plot dynamically-CodePudding

library(dagitty)
library(ggplot2)
library(ggdag)

get_jpg <- function(filename) {
  grid::rasterGrob(jpeg::readJPEG(filename), interpolate = TRUE)
    }
logo <- get_jpg("logo.jpg")

ex.1 <- dagitty("dag { 

X <- A -> B <- C -> Y
X <- B -> Y
X -> W -> Y
S-> T -> C
}")

exposures(ex.1) <- 'X'
outcomes(ex.1) <- 'Y'

tidy.1 <- ex.1 %>% 
  tidy_dagitty() %>%
  mutate(label = str_to_upper(name)) 


ggdag(tidy.1 , text = FALSE, use_labels = "label")   theme_dag()  
  theme_light()  
  annotation_custom(logo, xmin = 6.5, xmax = 8.5, ymin = -5, ymax = -8.5)  
  coord_cartesian(clip = "off")  
  theme(plot.margin = unit(c(1, 1, 3, 1), "lines"))

I have this code to put a JPG image within my plot. I understand that the xmin, xmax, ymin ymax coordinates are not aligning. Is there a way where I can display the image on the bottom right of the graph (similar to the ones shown here: https://www.markhw.com/blog/logos)? I want to do this dyanmically if possible without specifying coordinates because I'm not sure how ggdag plots x and y coordinates for the causal graphs.

Thanks!

CodePudding user response：

One option to achieve your desired result would be to position the logo by setting the coordinates via rasterGrob instead of via annotation_cutom. Making use of the example code in the post you linked in my code below I put the R logo on the bottom right. As you can see from the two examples I added this works fine independently of the range of the data and will put the logo always on the same position:

library(tidyverse)

download.file("https://www.r-project.org/logo/Rlogo.png", "logo.png")

get_png <- function(filename, x = unit(0.5, "npc"), y= unit(0.5, "npc"), 
                    width = NULL, height = NULL, gp = grid::gpar()) {
  grid::rasterGrob(png::readPNG(filename), interpolate = TRUE,
                   x = x, y = y, width = width, height = height, gp = gp)
}

species <- starwars %>% 
    count(species) %>% 
    filter(!is.na(species) & n > 1) %>% 
    arrange(-n) %>% 
    mutate(species = factor(species, species))

width = 3
l <- get_png("logo.png", 
             x = unit(1, "npc") - unit(width / 2, "lines"), 
             y = unit(-width, "lines"), 
             width = unit(width, "lines"))

p_fun <- function(x, width = 3) {
  ggplot(x, aes(x = species, y = n))  
    geom_bar(stat = "identity")  
    coord_cartesian(clip = "off")  
    theme_light()  
    theme(plot.margin = unit(c(1, 1, width, 1), "lines"))
}

p_fun(species)  
  annotation_custom(l)

p_fun(filter(species, n > 2))  
  annotation_custom(l)