[DATAFU-26] Resolve entropy UDF naming conventions

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0
• Assignee: jian wang
• Reporter: Matthew Hayes
• Created: 28/Jan/14 21:55
• Updated: 06/Mar/14 03:36
• Resolved: 03/Mar/14 18:32

Description

There are a couple issues with the naming of entropy UDFs that we should work out before the next release.

StreamingEntropy supports multiple estimation methods. Entropy however only support empirical. The supported constructors are also different as a result. Although Entropy's documentation states it computes the empirical entropy, I think the name itself may lead to confusion.

StreamingEntropy takes data the data in sorted order. Using this sorted data it computes count, which are then used to compute entropy. Entropy on the other hand takes counts directly and computes entropy. These counts need to be computed before calling it. Our convention in DataFu has been that "Streaming" implies that the data does not need to be sorted. So StreamingEntropy is in conflict with this.

My proposal is:

1) Rename Entropy to EmpiricalEntropy
2) Rename StreamingEntropy to Entropy
3) Clearly document why you would use EmpiricalEntropy over Entropy. It will be more efficient in some scenarios and we should explain this.

One open question I have is whether we should distinguish in the name somehow that EmpiricalEntropy accepts counts, not the actual items themselves. EmpiricalCountBasedEntropy seems verbose.