Ratio as fraction

[aleksandraduda2]

Currently, the API for ratio requires an integer to be entered, and sometimes we need to enter a fraction due to uneven allocation (change to numeric).

Correction for unequal allocation.

[kamilsi]

Thanks for the proposal.

My first reaction was that integers make sense because we assign whole people, and that is true for block-based randomization where blocks must be feasible. I do see your point for probability-based approaches like minimization, where only proportions matter and any positive numeric vector is equivalent up to scaling.

Practically, though, this is deeper than changing an assertion. Our DB schema stores ratio as INT and the tests assume integers, so switching to numeric would require a migration and broader changes.

Given that the difference is mostly cosmetic in practice (you can multiply 0.333 by 1000 and submit 333:667, or use a helper to scale to minimal integers), I suggest we keep integers for now. We can revisit native numeric input if we gather strong usability evidence that it meaningfully reduces errors or friction, ideally with a small helper that converts proportions to integers as a first step.