Global Base Maps Produced With OpenAlex
You can download all maps in a ZIP file or each map individually:
Global Overlay Maps Produced With OpenAlex
You can also download the overlay maps discussed in the STI 2024 conference paper:
These following overlay maps were presented additionally in the corresponding full paper:
The map files of the overlay maps can be downloaded in the following ZIP file:
global_overlay_maps_levels_0_1_2_opal_aug23_py_2008-2022_kb.zip
We plan to update the maps on an annual basis shifting the publication year forward.
The base maps using OpenAlex from August 2024 with the time periods shifted a year forward can be downloaded
here.
Example overlay map for the Max Planck Institute for Solid State Research:
Methods
As an example, we provide the SQL for the time period 2008-2022. The SQL can be run based on an OpenAlex snapshot in a relational database:
select cd.id cited_concept, cg.id citing_concept, count(*) cit_rels from
fiz_openalex_rep_20230819_openbib.works_referenced_works r
join fiz_openalex_rep_20230819_openbib.works_concepts wcd on referenced_work_id=wcd.work_id
join fiz_openalex_rep_20230819_openbib.concepts cd on cd.id=wcd.concept_id
join fiz_openalex_rep_20230819_openbib.works wd on wd.id=wcd.work_id
join fiz_openalex_rep_20230819_openbib.works_concepts wcg on r.work_id=wcg.work_id
join fiz_openalex_rep_20230819_openbib.concepts cg on cg.id=wcg.concept_id
join fiz_openalex_rep_20230819_openbib.works wg on wg.id=wcg.work_id
where cd.level between 0 and 2 and cg.level between 0 and 2
and wg.publication_year-wd.publication_year between 0 and 5
and wg.publication_year between 2008 and 2022 group by cd.id, cg.id order by cd.id, cg.id;
When running this SQL in another environment, the schema name (fiz_openalex_rep_20230819_openbib, printed in bold) has to be adjusted. The SQL exports the citation relations between the concepts from an OpenAlex snapshot in a PostgreSQL database. This procedure needs large amounts of hard disc storage and large amounts of memory to store and analyze the OpenAlex data especially using longer time periods. The tables resulting from the abovementioned SQL (and adjusted versions for the other maps) were exported from the database and imported into VOSviewer (via "Create", "Create a map based on network data", "VOSviewer network file"). Map files were saved within VOSviewer. Analysis of the citation relations with VOSviewer needs large amounts of memory. We replaced the concept IDs with the corresponding concept labels (i.e., names) to produce interpretable maps. These map files were opened in VOSviewer to produce the images of the base maps. We used the following parameters to construct the base maps: clustering resolution of 1.25, minimum cluster size of 500, label size variation of 0.2, and scale of 0.5.
For overlaying data on the global base maps, the following steps should be done: (1) The column "weight<papers>" needs to be replaced with the data to be overlaid. (2) The labels of the concepts without documents in the focus dataset should be removed and a color that does not occur in the global base maps should be chosen. (3) The value in the column "weight<papers>" for concepts without papers from the focal unit should be removed.
Note that the column header "weight<links>" in the base maps should be replaced by "weight<papers>".
