Don't allow log transform if anything is negative, even if all the data is
Don't allow log transform if anything is negative, even if all the data is

Originally I was thinking of using D3's log scales, whcih can handle logs when
the entire dataset is negative. But instead I'm just taking the log manually,
so I need to only allow log transformations when all the data is positive.

capnrefsmmat/regressomatic,capnrefsmmat/regressomatic,capnrefsmmat/regressomatic