(This article was first published on theBioBucket*, and kindly contributed to R-bloggers)
Since library() and require() only accept input with length(input) = 1 it is necessary to make repeated calls - this can be quite annoying.. So, HERE is a little wrapper function for convenient package installation / loading. It installs packages if they are missing and loads them if there were not loaded yet. I have put it to my RProfile.site so I can conveniently install / load packages with only one call and am quite content with it..
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Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).