Friday, June 7, 2019

Upgrades to research context in Nomisma's user interface

After several days of development, I have pushed some significant changes to the Nomisma.org user interfaces regarding additional context for certain types of entities defined in the system. Building on recent advancements that I made in increasing the complexity of typological and metrical visualizations in both Nomisma and the Numishare platform (specifically for Hellenistic Royal Coinages), I have introduced the same sorts of queries for the geographic APIs (that serialize SPARQL queries for mints, findspots, and hoards associated with a Nomisma concept into GeoJSON for display in Leaflet) and the list of related coin types.

Using the relationships inherent in Nomisma's data, we are now able to visualize the geographic distribution of corporate authorities, dynasties, and people appearing on portraits. For example, in order to generate a map illustrating the distribution of mints for the entire Seleucid Empire, the SPARQL query will search for coin types with an nmo:hasAuthority of a person who has an org:hasMembership/org:organization of http://nomisma.org/id/seleucid_empire.

In introducing this new level of complexity, I rewrote a significant portion of the pipelines underlying these URIs to migrate from a large series of hand-coded SPARQL templates in which small portions were replaced with simple string replacements to a more generalizable and flexible system built around using XSLT to generate a complex XML metamodel for a SPARQL query, which is then serialized by another set of XSLT templates into the SPARQL text that is POSTed to the endpoint.

New interface for http://nomisma.org/id/seleucid_empire, showing related coin types and a map of all Seleucid mints and known IGCH hoards and one single find.


As a result, the following improvements in mapping and/or related coin types have been applied to the following categories of SKOS concept:


Additionally, some updates were made to the distribution and metrical analysis SPARQL templates to query based on portraiture from the ID page (http://nomisma.org/id/faustina_i). This had previously not been possible--one had to use the purpose-built visualization interfaces and select "Portrait" as a facet.

The distribution of deities between Faustina and Antoninus Pius, as generated on the ID page for Faustina.

Having migrated to this new metamodel system for the generation of GeoJSON for geographic queries, it will be possible to enhance the complexity to iterate beyond queries about one particular Nomisma concept to queries that involve more than one parameter (such as those in the distribution and metrical visualization interfaces). That is to say, it will be possible eventually to not only generate a map showing the mints that produced tetradrachms, and where tetradrachms have been found in hoards, but where the tetradrachms of Ptolemy I have been produced and found. While Numishare contains a map interface that enables the display of mints pertaining to a query (driven by Apache Solr, the search index for Numishare), the indexing of findspots into Solr was disabled a year or two ago due to problems with scaling and the wait time for indexing a type corpus as large as OCRE. The next step is to rewrite the Numishare map interface to interact with Nomisma's SPARQL endpoint directly to display mints and findspots (which always reflects the current data ingested into the Nomisma linked data cloud), rather than rely on Solr.

Another major update is looming on the horizon, probably to come within the next few weeks: enhanced data for Roman Imperial persons. Presently, Hellenistic kings have been thoroughly integrated with Nomisma URIs for dynasties and corporate entities, but these are lacking in the Roman world. The Nomisma.org Roman committee is currently working on a revised spreadsheet of people in order to add new dynasties and corporate bodies into the system, as well as start and end dates for the reigns of Roman emperors. This means that we can compare visual motifs between the Julio-Claudians and the Flavians or compare the change in weights of antoniniani between the Gallic Empire and the Roman Empire (Valerian to Gallienus) over the same time period.

Additionally, dynasties and corporate bodies will be introduced as facets in OCRE. We are also working on a spreadsheet of Roman provinces, which will also be introduced as facets in addition to historical regions. The Region facet in OCRE is currently a conflation of provinces and historical regions owing to inconsistencies in RIC's structure.

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