A dilution.stepsize argument might be useful

[SamT123]

Hi Sam!

I'm working with some data where titers are calculated by estimating ID50 by some curve fitting method, which gives continuous valued titers. In this case, a "<20" titer is not the same as "<=10", like it is for the 2-fold dilution data we normally work with. In this case, it would be good for ablandscapes to treat it as "<=20", rather than converting it to "<=10" (which I believe happens in the titers_to_logtiters function). I can get around this by converting "<20" to "<40" before I pass the titers to ablandscapes, but it would be not to have to do this. A nice way to do this might be to use a dilution.stepsize argument like in your meantiter package?

(When I've got a bit of time I might come back and implement this if you think it would be a useful addition)