when opts.scales.x.distr: 2, u.scales.x.min/max are indices

[leeoniya]

when opts.scales.x.distr: 2...

after calling .setScale('x', {min, max}), u.scales.x.min/max will actually be indices into data[0] rather than the indicated values. this is due to how the internals work to provide uniform spacing. e.g. it's not possilble to zoom in between data values when distr: 2. this will surely be re-visited anyhow as part of implementing log scales (#29).

this is surprising / non-uniform behavior, but is more of a papercut rather than a serious bug. the work-around is simply knowing that the actual scale's min has to be pulled by index from u.data[0][u.scales.x.min].

this is low priority because distr: 2 is already a niche case, and the cases when scales need to be read back after setting is even more niche. and in those cases, it's easily handled by the solution above.

[leeoniya]

closing this as "by design", see #311 (comment)