Data Analysis with R, Second Edition - Second Edition

Exercises

Practice the following exercises to revise the concepts learned in this chapter:

• How did we waste computation in the similarity_matrix function?
• Both the Last.fm and the MusicBrainz API have a count value associated with each tag, which can be taken to represent the extent to which the tag applied to the artist. By ignoring this field, in both cases we implicitly used a count of 1 for every tag, making well-fitting tags just as important as relatively less well-fitting ones. Rewrite the code to take count into account, and weigh each tag proportionally to its count value. This will be challenging, but it will be invaluable for understanding the material. It will also boost your confidence as an R programmer once you finish. Go ...