The requirement only to exhibit the features of a sigmoid was intentionally left vague to allow for creative entries, not to act as a loophole for rules lawyers.On the other hand, if the rules are so vague that even otherwise correct entries are wrong and can be disqualified if you're having a bad day, then there is no contest.If the goal of the contest were to plot a sigmoid, then the fastest entry would not actually draw a sigmoid at all, but instead calculate where to plot. Nevermind whether doubles are appropriate for this purpose. Do you intend to write code that would draw a sigmoid curve based on the output, or will those kinds be disqualified also? Would that be weasel code?
Whatever, here's one.