Started work on an object-based version of the data structure. I hope to have complex enough objects that the data structure containing them is simple, and that each trial object can modify the svg object associated with it. I've got a test set of 20 objects appearing by year in default colours. The main part of the work will be rewriting the interactive code so that when a user clicks on filter checkbox, the appropriate values are modified in the grid of trial objects and then each of those modifies the svg object associated.
Prior to that, tidied up a few minor errors in the all-array version of the site and sent email to SD updating him on improvements I've made and getting input from him on exactly what data fields and values to use in the remaining categories he wishes to sort and hide/show by.