I'm trying to figure out if it's possible to do week over week aggregations and comparisons in Kibana in order to show a week over week % difference? I basically want to do this:
[Thursday2-Thursday1]/Thursday1
Is this possible?
Not currently. You could possibly show these two values side-by-side (for instance, using date range aggregations in Kibana 4.1), but calculating a ratio will require support for arithmetic in aggregations -- luckily, this is coming in Elasticsearch 2.0: https://github.com/elastic/elasticsearch/issues/9876