# sigmoid function fail

Plot the sigmoid function.

$sig(u)=\frac{1}{1+e^{-u}}$

Does this look sigmoidal to you?

A result that confused me until [Thanks, Sasha] I noticed the tick values on my x-axis, which matplotlib selected unintelligently.  If we simply correct the plot domain.

xs = [0.01*x for x in range(-1000,1000)]

I would like to know more about how different plotting packages, such as matplotlib and ggplot2 in R, select default values for xrange and yrange.