Github user cestella commented on the issue:
https://github.com/apache/incubator-metron/pull/257
The issue around the `StellarScientificTest` change is that merging
t-digests is not precisely the same as adding the same data to one t-digest.
Whether this is a bug in the t-digest code or whether it's an artifact of the
theory, I don't know. Because this test is using low amounts of data, it's
prone to a bit of jitter it seems and the compression level specified before
isn't sufficient to ensure that the epsilon chosen (1e-2) is sufficient for
repeated runs. I tightened up the compression level to 150 (which is still
quite sensible) to make sure we can support at least 1e-2 accuracy for normally
distributed data across 100 runs of 1000 elements.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
