New version of fingerprint (3.4.9) – faster Dice similarity matrices

I’ve just pushed a new version of the fingerprint package that contains an update provided by Abhik Seal that significantly speeds up calculation of pairwise similarity matrices when using the Dice similarity method. A ran a simple comparison using different numbers of random fingerprints (1024 bits, with 512 bits set to one, randomly) and measured […]

Chunking lists in R

A common task for is to run database queries on gene symbols or compound identifiers. This involves constructing an SQL query as a string and sending that off to the database. In the case of the ROracle package, the query strings are limited to a 1000 (?) or so characters. This means that directly querying […]

Software for the “Federation of Independent Scientists”

A few days back, Derek Lowe posted a comment from a reader who suggested a way to approach the current employment challenges in the pharmaceutical industry would be the formation of a Federation of Independent Scientists. Such a federation would be open to consultants, small companies etc and would use its size to obtain group […]

“Type-ahead” substructure searches

The other day I was exchanging emails with John Van Drie regarding open challenges in cheminformatics (which I’ll say more about later). One of his comments concerned the slow speed of chemical searches Google searches are screamingly fast, so fast that the type-ahead feature is doing the search as you key characters in.  Why are all chemical […]

Substructure Searches – High Speed, Large Scale

My NCTT colleague, Trung Nguyen, recently announced a prototype chemical substructure search system based on fingerprint pre-screening and an efficient in-memory indexing scheme. I won’t go into the detail of the underlying pre-screen and indexing methodology (though the sources are available here). He’s provided a web interface allowing one to draw in substructure queries or […]