The export_png()
R ggvis包中的函数需要我们有程序vg2png
从 node.js 模块安装vega
。
(来源:R 文档 http://www.rdocumentation.org/packages/ggvis/functions/export_png )
我在 Windows 上安装了 Node 和 npm,然后运行npm install vega
.
这是我运行时得到的输出npm install vega
:
C:\Users\username>npm install -g trifacta/vega
\
> [email protected] /cdn-cgi/l/email-protection install C:\Users\username\AppData\Roaming\npm\node_modules\vega\node_modules\canvas
> node-gyp rebuild
|
C:\Users\username\AppData\Roaming\npm\node_modules\vega\node_modules\canvas>node "C:\Program Files\nodejs\node_modules\npm\bin\node-gyp-bi
n\\..\..\node_modules\node-gyp\bin\node-gyp.js" rebuild
Node Commands
Syntax:
node {operator} [options] [arguments]
Parameters:
/? or /help - Display this help message.
list - List nodes or node history or the cluster
listcores - List cores on the cluster
view - View properties of a node
online - Set nodes or node to online state
offline - Set nodes or node to offline state
pause - Pause node [deprecated]
resume - Resume node [deprecated]
For more information about HPC command-line tools,
see http://go.microsoft.com/fwlink/?LinkId=120724.
C:\Users\username\AppData\Roaming\npm\vg2svg -> C:\Users\username\AppData\Roaming\npm\node_modules\vega\bin\vg2svg
C:\Users\username\AppData\Roaming\npm\vg2png -> C:\Users\username\AppData\Roaming\npm\node_modules\vega\bin\vg2png
[email protected] /cdn-cgi/l/email-protection C:\Users\username\AppData\Roaming\npm\node_modules\vega
├── [email protected] /cdn-cgi/l/email-protection ([email protected] /cdn-cgi/l/email-protection)
├── [email protected] /cdn-cgi/l/email-protection ([email protected] /cdn-cgi/l/email-protection)
├── [email protected] /cdn-cgi/l/email-protection
├── [email protected] /cdn-cgi/l/email-protection ([email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, tunnel-agen
[email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection
0.1, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection)
├── [email protected] /cdn-cgi/l/email-protection ([email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection, [email protected] /cdn-cgi/l/email-protection)
└── [email protected] /cdn-cgi/l/email-protection ([email protected] /cdn-cgi/l/email-protection)
我不确定它是否安装正确。现在,当我跑步时:
mtcars %>%
ggvis(x = ~wt) %>%
export_png()
我收到以下错误:
写入文件plot.png
vega_file(vis, file = file, type = "png") 中的错误:
未找到转换程序 vg2png。
是否有在 Windows 上安装 vega 的特定方法可以解决此错误?