Suppose you want to perform topic modeling of the abstract extracted from PubMed by doing a literature search using "Deep Learning" as keyword. The objective is to see what the possible topics and subject areas are where the deep learning approach has been used. In this recipe, your ultimate task is to search the literature through PubMed, extract the abstract, and finally do the pre-processing. The search keyword is "Deep Learning". Also, your search will be restricted to the first 50 abstracts.

Here are the required libraries for this recipe:

• pubmed.mineR
• RISmed

If you don't have these libraries already installed on your computer, then run the following code to install them:

    install.packages(c("pubmed.mineR", "RISmed"), dependencies = TRUE)