将gvisGeoMap对象保存为png图片

Question

将gvisGeoMap对象保存为png图片

4

如何将googleVis中的gvis对象保存为png格式？ ggvis有export_png函数，但该函数无法用于googleVis。

我看到有人问过类似的问题，但真的没有其他方法吗？

test_data <- data.frame(count=c(1,2,5),group=c("Australia","Austria","China"))

p <- gvisGeoMap(test_data,locationvar='group',numvar='count',options=list(dataMode='regions',colors="['0x0000ff', '0xff0000']"))

plot(p)

- Jan Stanstrup

也许这篇帖子可以帮助你。 - Anders Ellern Bilgrau

我尝试过了。正如我所说，我不认为它能够工作（至少在我尝试时没有成功，如果我错了请纠正我），因为那篇文章是关于使用ggvis的export_png，而不是googleVis。 - Jan Stanstrup

我发现这个问题在这里也被问到了，但没有答案：http://stackoverflow.com/questions/33546394/r-googlevis-to-png-file?rq=1 - Jan Stanstrup

走一条漫长的路，你可以创建一个非常简单的闪亮应用程序（只使用你的绘图），并使用webshot包中的appshot()函数进行网页截图。 - MLavoie

2个回答

0

目前，webshot2 可用。我在这里发布了我的解决方案。

- Patrick

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- khrm · Accepted Answer

有很多方法可以进行此操作，但结果难以预测。以下是一些技巧：

Xvfb, imagemagick and browser.

You need to have all three of them installed. This won't work on Windows. I am assuming you have install xvfb and imagemagick. You start xvfb server in shell:-
```
Xvfb :3 -screen 0 1024x768x24 &
```
Now in R, you can print the file as html:
```
print(p, file="p.html")
```
Now a system call:
```
system("DISPLAY=:3      firefox     g1.html  &")
```
Now print the file using:
```
system("DISPLAY=:3 import -window root p.png")
```
You will get the file as p.png. You can use some other browser also like chrome.
Using wkhtmltopdf package.

After installing wkhtmltopdf and having it in your PATH, use system call:
```
print(p, file="p.html")
system("wkhtmltoimage --enable-plugins --javascript-delay 10000   p.html p.png")
```
Results aren't predictable. Sometime flash doesn't work. Sometime it works for some platform. I couldn't reproduce like my first solution. (For OP, this solution worked. This is a cross platform solution.)
As shiny app, phantomjs and webshot:

Assuming you have printed the file that I have given, create a shiny app using following methods:
```
mkdir app # Create App Directory
# Create UI
cat <<- EOF > app/ui.R
library(shiny)

shinyUI(fluidPage(
  titlePanel("Google Chart"),
  mainPanel(
    includeHTML("../g1.html")
  )
))    
EOF
# Create server
cat <<- EOF > app/server.R
library(shiny)
shinyServer(function(input, output) {
})
EOF
```
Now install phantomjs:
```
npm install -g phantomjs
```
In r:-
```
install.packages("webshot")
appshot("app", "p.png")
```
You will see that you won't get flash charts because phantomjs now doesn't support flash. So this method too is limited. Only first method will work but it's not cross platform. But you can proceed with that approach in windows by using equivalent stuff.