"Is there support for µ±σ instead of [low,high] in the works? "
- There used to be. I'll be considering ways of adding it back.
"Or support for numerical distributions?"
- By numerical distributions do you mean discreet distributions: like, a 40% of being '8' and a 60% chance of being '6'? If so, the answer is no. However, if you use the ternary operator it is possible to do very simple versions of this now. We do support totally random picks of different numbers though, using the pickRandom([3,5,3]) function. http://mathjs.org/docs/reference/functions/pickRandom.html
I meant more along the lines of a user-entered histogram. But that's roughly the same as what you're talking about. It does seem that such a thing must roughly correspond to some internal portion of Guesstimate, anyway. So for an advanced user to punch a distribution in would be handy. May be out-of-scope for this project? I guess really I'm looking for a way to error propagate my home-grown datasets :)
"Or support for numerical distributions?" - By numerical distributions do you mean discreet distributions: like, a 40% of being '8' and a 60% chance of being '6'? If so, the answer is no. However, if you use the ternary operator it is possible to do very simple versions of this now. We do support totally random picks of different numbers though, using the pickRandom([3,5,3]) function. http://mathjs.org/docs/reference/functions/pickRandom.html