如何用Patchwork合并Plotly与ggplot2图表为分面并导出PDF

我尝试用Patchwork的(Treemap_plotly/barchart_ggplot2)命令将Plotly树形图和ggplot2柱状图合并成分面布局并导出为PDF，但该命令无法生效。相关代码如下：

library(ggplot2)
library(plotly)
library(dplyr)
library(patchwork)

## 1.Plotly
dt=data.frame(
  types= rep("stories",10),
  kind= c('kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1'),
  values=seq(1:10))

Treemap_plotly<-plot_ly(data = dt,
                 type= "treemap",
                 values= ~values,
                 labels= ~kind,
                 parents=  ~types,
                 domain= list(column=0),
                 name = " ",
                 textinfo="label+value+percent parent")%>%
            layout(title="Treemap")

## 2.ggplot2
df1 <- data.frame(dose=c("D0.5", "D1", "D2"),
                 len=c(4.2, 10, 29.5))

barchart_ggplot2<-ggplot(data=df1, aes(x=dose, y=len)) +
          geom_bar(stat="identity", fill="steelblue")+
          geom_text(aes(label=len), vjust=-0.3, size=3.5)+
          theme_minimal()

# 尝试合并（无效）
(Treemap_plotly/barchart_ggplot2)

问题原因 #

Patchwork仅支持ggplot2对象的组合，而Plotly生成的是htmlwidgets类型对象，两者底层结构不同，无法直接用Patchwork语法合并。

解决方案 #

方案1：将Plotly转为静态图后用Patchwork合并

先把Plotly图表转为静态图片，再转为ggplot兼容的对象，之后用Patchwork组合并导出PDF：

library(ggplot2)
library(plotly)
library(dplyr)
library(patchwork)
library(webshot2)
library(png)

# 生成两个图表（代码同问题部分，可复用）
dt=data.frame(
  types= rep("stories",10),
  kind= c('kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1'),
  values=seq(1:10))

Treemap_plotly<-plot_ly(data = dt,
                 type= "treemap",
                 values= ~values,
                 labels= ~kind,
                 parents=  ~types,
                 domain= list(column=0),
                 name = " ",
                 textinfo="label+value+percent parent")%>%
            layout(title="Treemap")

df1 <- data.frame(dose=c("D0.5", "D1", "D2"),
                 len=c(4.2, 10, 29.5))

barchart_ggplot2<-ggplot(data=df1, aes(x=dose, y=len)) +
          geom_bar(stat="identity", fill="steelblue")+
          geom_text(aes(label=len), vjust=-0.3, size=3.5)+
          theme_minimal()

# 将Plotly转为静态图片，再转为ggplot对象
tmp_png <- tempfile(fileext = ".png")
save_image(Treemap_plotly, tmp_png)
treemap_static <- ggplot() + 
  annotation_raster(readPNG(tmp_png), xmin=-Inf, xmax=Inf, ymin=-Inf, ymax=Inf) +
  theme_void()

# 合并布局并导出PDF
combined_plot <- treemap_static / barchart_ggplot2
ggsave("combined_plots.pdf", combined_plot, width=8, height=10)

方案2：用htmltools组合后导出为PDF

将两个图表组合成HTML页面，再转为PDF（若需保留交互性，可直接导出为HTML）：

library(ggplot2)
library(plotly)
library(dplyr)
library(htmltools)
library(webshot2)

# 生成两个图表（代码同问题部分）
dt=data.frame(
  types= rep("stories",10),
  kind= c('kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1','kind_2','kind_3','kind_1'),
  values=seq(1:10))

Treemap_plotly<-plot_ly(data = dt,
                 type= "treemap",
                 values= ~values,
                 labels= ~kind,
                 parents=  ~types,
                 domain= list(column=0),
                 name = " ",
                 textinfo="label+value+percent parent")%>%
            layout(title="Treemap")

df1 <- data.frame(dose=c("D0.5", "D1", "D2"),
                 len=c(4.2, 10, 29.5))

barchart_ggplot2<-ggplot(data=df1, aes(x=dose, y=len)) +
          geom_bar(stat="identity", fill="steelblue")+
          geom_text(aes(label=len), vjust=-0.3, size=3.5)+
          theme_minimal()

# 将ggplot转为htmlwidget，组合成HTML页面
ggplot_html <- ggplotly(barchart_ggplot2)
combined_html <- tagList(
  tags$div(Treemap_plotly, style="width: 100%; height: 400px;"),
  tags$br(),
  tags$div(ggplot_html, style="width: 100%; height: 400px;")
)

# 保存临时HTML并转为PDF
tmp_html <- tempfile(fileext = ".html")
save_html(combined_html, tmp_html)
webshot(tmp_html, "combined_plots.pdf", vwidth=800, vheight=1000)

注意事项 #

• 方案1生成的是静态PDF，Plotly的交互性会丢失；方案2导出的PDF也是静态的，若需保留交互性可直接保存为HTML文件。
• 执行前需安装依赖包：install.packages(c("webshot2", "png", "htmltools"))

内容的提问来源于stack exchange，提问作者silent_hunter