adding images to flextable using Display() & as_image() in loop doesnot work

Question

I have a zip file which has multiple images of 2 types.1 -FrequencyRose images 2- EnergyRose images. I have created a flextable and then replacing the even rows with images and odd rows with the image titles using for loop . The loop is correctly displaying the titles but its only printing the last read image of each type mulitple times instead of actually printing all the images as per loop count.

img.file <- unzip("D:\\Mast_Image Files.zip")
fr_files <- img.file[grepl(paste("FrequencyRose", collapse = "|"), img.file)]
er_files <- img.file[grepl(paste("EnergyRose", collapse = "|"), img.file)]

fr_files has 3 image file paths and same with er_files click

num_masts = length(img.file)

c1 = rep("Freq_rose",num_masts)
c2 = rep("Energy_Rose",num_masts)

df = data.frame(c1,c2)


dfft = flextable(df)

sso=seq(1,num_masts,2)
sse=seq(2,num_masts,2)

for (g in 1:(num_masts/2)){

  ff.img = fr_files[g]
  ef.img = er_files[g]

  dfft2 = dfft %>%
    display(
      i = sse[g], col_key = "c1", pattern = "{{img}}",
      formatters = list( img ~ as_image(c1,
                                        src = ff.img, width = 3, height = 3))) %>%

    display(
      i = sse[g], col_key = "c2", pattern = "{{img}}",
      formatters = list( img ~ as_image(c2,
                                        src = ef.img, width = 3, height = 3))) %>%

    display(
      i = sso[g], col_key = "c1", pattern = paste("Freq_Rose","mast",g)) %>%

    display(
      i = sso[g], col_key = "c2", pattern = paste("Energy Rose","mast",g))


}

this loop is able to produce titles correctly but the only the fr_files[3], er_files[3] is looping over all the even rows of corresponding columns. output is as :final results . could not find the issue.

score 1 · Answer 1 · answered Feb 06 '19 at 10:32

I can't reproduce your example (I don't have the images).

library(ggplot2)
library(tidyverse)
library(flextable)

# a data example ----
zz <- iris %>% 
  group_by(Species) %>% 
  summarise( n = n(), avg = mean(Petal.Length), 
             img_path = paste0( unique(as.character(Species)), ".png"),
             gg = list(ggplot(tibble(Sepal.Length, Petal.Width), aes(Sepal.Length, Petal.Width)) + geom_point() + theme_minimal())
             )
zz
# create the png ----
walk2(zz$gg, zz$img_path, function(gg, path){
  png(filename = path, width = 300, height = 300)
  print(gg)
  dev.off()
})

From there you have everything you need and the flextable commands could be:

# create the flextable -----
flextable(zz, col_keys = c("Species", "n", "avg", "plot")) %>% 
  # here, i is selecting only odd rows 
  compose(i = ~ seq_along(Species) %% 2 > 0, j = "plot", value = as_paragraph(as_image(img_path, width = 300/72, height = 300/72))) %>% 
  theme_box() %>% 
  autofit()

Thanks for the response David. But when I was trying to use compose(...as_paragraph()) instead of display() it was throwing an error "as_paragraph not found". — Karthik Nani, Feb 06 '19 at 12:15

adding images to flextable using Display() & as_image() in loop doesnot work

1 Answers1