Hash Tables in Mathematica
This week, after downloading citing and related paper numbers of around 50.000 papers that were presented as results to various simple searches in PubMed, we wanted to have a way to find out most cited authors. Both extremely new to Mathematica, we were yet to see anything that looked or behaved like hash tables so our first approach looked like this: recordsOfAuthor[author_]:= Select[ records, Composition[MemberQ[#, author]&, authorsOf] ] where records were a list of XMLElement s containing EndNote X3 records (these roughly correspond to PubMed search results). Now I am not the guy to immediately understand the O-complexity of any given code, yet the first thing I had told my friend after we had finished downloading the citation numbers and right before we started coding the rest of our analysis tools was that we definitely needed to either find out how to use hash tables in Mathematica or do the whole thing in another language, otherwise we might have some headache.