I have data that has a weighting field and I'd like to visualize the weighted average in Kibana4. Is it possible to visualize this query in Kibana4?
On Friday, 9 January 2015 23:42:42 UTC+1, Kallin Nagelberg wrote: > > The current 1.4 docs mention that the scripted_metric aggregation is > experimental, and to share our usages. I've found a really great use on our > project so I thought I'd share! > > While the 'stats' metric provides great data like 'sum' and 'average', we > needed to calculate a weighted average. In this case, the weighting field > is 'principal_amount', and the field we'd like the metric on is 'rate'. A > CURL for this agg is here: > > curl -XGET "http://localhost:9200/my_index/_search"; -d' > { > "size": 0, > "aggs": { > "test_script": { > "scripted_metric": { > "init_script": "_agg[\"numerator\"] = []; _agg[\"denominator\"] = > [];", > "map_script": "_agg.numerator << (doc[\"principal_amount\"].value > * doc[\"rate\"].value); _agg.denominator << > doc[\"principal_amount\"].value", > "combine_script" : "num_sum = 0; den_sum = 0; for (t in > _agg.numerator) { num_sum += t }; for (t in _agg.denominator) { den_sum += > t };return [num_sum: num_sum, den_sum: den_sum]", > "reduce_script" : "num_sum = 0; den_sum=0; for (a in _aggs) { > num_sum += a.num_sum; den_sum += a.den_sum; }; return num_sum/den_sum" > } > } > } > }' > > For reference, a weighted average is defined here (it's pretty simple): > http://www.investopedia.com/terms/w/weightedaverage.asp > > Without this great new aggregation type, I guess I'd have to index the > product of 'rate' and 'principal_amount' so that I could run a stats agg on > that. It would work, but not as clean. > > One thing I notice here is that there is quite a bit of redundancy between > the 'combine' and 'reduce' scripts. I haven't fully explored what the most > concise representation might look like, but it could be something to think > about as this aggregation develops. > > Thanks for including it! > -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/5774a2de-1c4b-4e91-865b-b95522690db7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
