Openrefine: Document Transposition functions

[ostephens]

As per #1214 there is currently a lack of documentation around how the transposition functions work. Add to the wiki a description of how each of the transposition functions work and examples of data scenarios where they can be useful

[thadguidry]

I elect.... Owen to work on this :)

[ettorerizza]

@ostephens If I'm not mistaken, "columnize by key-value" works in the same way as the spread/cast functions in R, while "transpose cells across columns into rows" is the equivalent of gather/melt. The documentation and tutorials of these two functions can therefore serve as a source of inspiration, I believe.

[wetneb]

A wikidatan is interested in something that looks like transposition functions, but I could not point them to any documentation for that, so I gave the link to this issue:
https://www.wikidata.org/wiki/User:John_Cummings/Useful_spreadsheet_processes_for_Wikidata#Select_every_Nth_line

[wetneb]

I am working on this today, with the intention to provide an example of operation documentation, which can hopefully be used as a gold standard to document other operations.

[wetneb]

Here is an attempt for key/value columnize:

• Rendered version
• Source

[wetneb]

This is done for the key-value columnize operation - it remains to be done for other transpose operations.

https://docs.openrefine.org/operations/key_value_columnize.html