Wide to long panel function

[jseabold]

This has been a pain point for me. The use case is pretty specific. Cf. reshape long in stata.

https://gist.github.com/jseabold/6653108

Can add tests and make a PR, if desired.

[jtratner]

seems reasonable, mostly an extension to melt, right?

[jreback]

maybe just add a kw to melt to 'do' this?

[jseabold]

yeah, i just was tired of "thinking" whenever i had to use melt

[cpcloud]

@jseabold FWIW I have the opposite problem: I always have to think when using pivot et al. :)

Also reshape2's melt handles ND arrays, so maybe it should just "work" without a kwarg

[cpcloud]

http://stackoverflow.com/questions/9106203/r-combine-a-3d-matrix-and-single-vector-then-select-certain-month-data