r - 在循环中使用 Display() 和 as_image() 将图像添加到 flextable 不起作用

Question

我有一个 zip 文件，其中包含 2 种类型的多个图像。1-FrequencyRose 图像 2-EnergyRose 图像。我创建了一个 flextable，然后使用for loop将偶数行替换为图像，将奇数行替换为图像标题。该循环正确显示标题，但它仅多次打印每种类型的最后读取图像，而不是根据循环计数实际打印所有图像。

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 有 3 个图像文件路径，与 er_files click相同

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))


}

此循环能够正确生成标题，但唯一的 fr_files[3]、er_files[3] 正在循环对应列的所有偶数行。输出为：最终结果。找不到问题。

标签： rfor-loopr-markdownflextableofficer

Answer 1

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()