如何在R中的绘图上放置多个png？

发布于 2025-01-11 06:19:15 字数 1232 浏览 0 评论 0原文

此处和此处。但是，他们并没有完全解决我的问题。

我正在尝试绘制热图。但然后在热图的每个图块上，我想放置一个 png。到目前为止，这是我的代码：

library(ggplot2)
library(png)
library(grid)

# get png
img <- readPNG(system.file("img", "Rlogo.png", package="png"))
g <- rasterGrob(img, interpolate=TRUE)

# create heatmap
x <- LETTERS[1:5]
y <- paste0("var", seq(1,5))
data <- expand.grid(X=x, Y=y)
data$Z <- runif(25, 0, 5)

# Heatmap 
p <- ggplot(data, aes(X, Y, fill= Z)) + 
  geom_tile() + 
  theme(aspect.ratio = 1)

# place png
p +
  annotation_custom(g, xmin = 0.5, xmax = 1.5, ymin = 0.5, ymax = 1.5)

上面的代码绘制了这个：

但我想做的是将 png 放在热图的每个图块上。现在，我可以像这样检索每个图块的坐标：

b <- ggplot_build(p)
b$data[[1]]$xmin
b$data[[1]]$xmax
b$data[[1]]$ymin
b$data[[1]]$ymax

但我不知道如何将 png 放置在每个图块上。我希望不必为每个图块都有一个 annotation_custom 参数。我正在尝试使该过程稍微自动化。

有什么办法可以做到这一点吗？

原文

Similar questions have been asked here and here. However, they don't exactly solve my issue.

I'm trying to plot a heatmap. But then on every tile of the heatmap, I want to place a png. Here's my code so far:

library(ggplot2)
library(png)
library(grid)

# get png
img <- readPNG(system.file("img", "Rlogo.png", package="png"))
g <- rasterGrob(img, interpolate=TRUE)

# create heatmap
x <- LETTERS[1:5]
y <- paste0("var", seq(1,5))
data <- expand.grid(X=x, Y=y)
data$Z <- runif(25, 0, 5)

# Heatmap 
p <- ggplot(data, aes(X, Y, fill= Z)) + 
  geom_tile() + 
  theme(aspect.ratio = 1)

# place png
p +
  annotation_custom(g, xmin = 0.5, xmax = 1.5, ymin = 0.5, ymax = 1.5)

The above code plots this:

But what Im trying to do is place the png on every single tile go the heatmap. Now, I can retrieve the coordinates for each tile like so:

b <- ggplot_build(p)
b$data[[1]]$xmin
b$data[[1]]$xmax
b$data[[1]]$ymin
b$data[[1]]$ymax

But I don't know how to place the png on every tile. I was hoping to not have to have an annotation_custom argument for every single tile. I'm trying to somewhat automate the process.

Is there any way that this can be done?

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徒留西风 2025-01-18 06:19:15

您可以循环添加注释

xmin = b$data[[1]]$xmin
xmax = b$data[[1]]$xmax
ymin = b$data[[1]]$ymin
ymax = b$data[[1]]$ymax

for (i in seq_len(nrow(data))) {
  p = p + annotation_custom(g, xmin = xmin[i], xmax = xmax[i], 
                               ymin = ymin[i], ymax = ymax[i])
}

You can add the annotations in a loop

xmin = b$data[[1]]$xmin
xmax = b$data[[1]]$xmax
ymin = b$data[[1]]$ymin
ymax = b$data[[1]]$ymax

for (i in seq_len(nrow(data))) {
  p = p + annotation_custom(g, xmin = xmin[i], xmax = xmax[i], 
                               ymin = ymin[i], ymax = ymax[i])
}