修改 alpha 后，图像透明度会受到影响（透明）！图表2

Question

我正在尝试将以下图像添加到此条形图中，但是，正如您所看到的，当我将其设置为 pdf 时，图像变得透明了！ alpha 为 0.45。如果我将 alpha 设置为 1，那么它应该会显示！

在这个例子中，我只使用 alpha 来使第二个闪避条形图透明，但包含的 png 应该是 100% 颜色不褪色！你知道有什么方法可以做到这一点吗，我仍然希望那些条带随着 alpha 逐渐消失，但图像完好无损。

请注意，如果您只是运行在您的 Rmarkdown 中使用此图片，预览中的图像看起来非常好，当我们编织并生成 pdf 时，问题就来了！

请帮忙

这是 knitr 到 pdf 时图表上马图像的褪色结果：

实际图标是：

我使用的代码在这里：

library(ggplot2)
library(reshape2)
library(grid)

#Create DataFrame
x <- c(5,17,31,9,17,10,30,28,16,29,14,34)
y <- c(39,6,3,4,1,6,7,2,9,10,3,4)
day <- c("d1","cd2","d3","d4","d5","d6","d7","d8","d9","d10","d11","d12")
df1 <- data.frame(x, y, day)

#Sort the table according to x values
df1$day <- factor(df1$day, levels = df1[order(-df1$x), 3])

#for each day (e.g. 1) you will have all combinations of x and y (e.g. day = 1, x = 5, y = 5), (e.g. day = 12, x=34, y=4). variable becomes x and y, and value becomes the value of either x or y.
df2 <- melt(df1, id.var="day", measure.var=c("x","y"))
#head(df2)

#Image
img <- readPNG("imgs/unnamed.png")
g <- rasterGrob(img, interpolate=TRUE)


barcolors <- c("#428953", "#CE2929", "#A3DD57", "#77E599", "#5675D6", "#65ECEF", "#FF8B07", "#D0B100", "#636363", "#D0B100", "#CE2929", "#428953")

ggplot(df2, aes(x=day, y=value)) + 
    geom_bar(aes(fill=day, alpha=variable), stat="identity", width = .75, position = position_dodge(width=.8)) +
    scale_alpha_manual(values=c(1, .45)) +
    scale_fill_manual(values= barcolors) +
    theme_bw() + 
    theme( panel.grid.major.x = element_blank(),
       legend.position="none",
       legend.text=element_text(size=14),
       legend.title = element_blank(),
       axis.title.x = element_blank()) +
    annotation_custom(g, xmin=.7, xmax=1.3, ymin=35, ymax=40) + ylim(0,40)

Answer 1

这可能不是原因的解释，而是可行的解决方案。

library(tidyverse)
library(reshape2)
library(grid)
library(png)

df = tibble(
  x = c(5,17,31,9,17,10,30,28,16,29,14,34),
  y = c(39,6,3,4,1,6,7,2,9,10,3,4),
  day = c("d1","cd2","d3","d4","d5","d6","d7","d8","d9","d10","d11","d12")
) %>% mutate(
  day = day %>% fct_reorder(x)
) %>% pivot_longer(cols=1:2, names_to = "variable", values_to = "value")

img <- readPNG("imgs/unnamed.png")
g <- rasterGrob(img, interpolate=TRUE)

barcolors <- c("#428953", "#CE2929", "#A3DD57", "#77E599", "#5675D6", "#65ECEF", "#FF8B07", "#D0B100", "#636363", "#D0B100", "#CE2929", "#428953")
df %>% ggplot(aes(x=day, y=value, alpha=variable)) + 
  geom_bar(aes(fill=day), stat="identity", width = .75, position = position_dodge(width=.8))+
  annotation_custom(g, xmin=.7, xmax=1.3, ymin=35, ymax=40)+
  annotation_custom(g, xmin=.7, xmax=1.3, ymin=35, ymax=40)+
  scale_alpha_manual(values=c(1, .45)) +
  scale_fill_manual(values= barcolors) +
  theme_bw() + 
  theme( panel.grid.major.x = element_blank(),
         legend.position="none",
         legend.text=element_text(size=14),
         legend.title = element_blank(),
         axis.title.x = element_blank()) + 
  ylim(0,40)

以下是 pdf 文件的摘录。这是来自 HTML 文件的片段。

修改 alpha 后，图像透明度会受到影响（透明）！图表2

Image transparency is affected (transparent) once alpha is modified! ggplot2

pdf

r

ggplot2

xelatex

r-markdown