I just made a new package export
to easily export R graphs to Office (Word, Powerpoint), see
https://cran.r-project.org/web/packages/export/index.html and
for demo https://github.com/tomwenseleers/export.
Typical syntax is very easy, e.g.:
install.packages("export")
library(export)
library(ggplot2)
qplot(Sepal.Length, Petal.Length, data = iris, color = Species,
size = Petal.Width, alpha = I(0.7))
graph2ppt(file="ggplot2_plot.pptx", width=6, height=5)
Output is vector format and so fully editable after you ungroup your graph in Powerpoint. You can also use it to export to Word, Excel, Latex or HTML and you can also use it to export statistical output of various R stats objects.
This results in a fully editable, high quality Powerpoint graph in native Office vector-based DrawingML format, which you can also readily copy & paste as enhanced metafile if you like, and which unlike the EMFs exported from R also fully supports transparency.