我正在尝试运行gWidgetsRGtk2示例的前两行但我在CRAN中找不到glade库。所以gladeXMLNew（）函数失败了。有人可以提供帮助吗？
## This requires glade libraries to be installed before compiling RGtk2
options("guiToolkit"="RGtk2")
library(RGtk2)
library(gWidgets)
library(gWidgetsRGtk2)
gladeFile <- system.file("examples/t.test.glade",package="gWidgetsRGtk2")
GUI <- gladeXMLNew("t.test.glade")
提前谢谢