[Someone]

I'm not sure whether this library supports it, but if you plot a function, a smart plotting library will evaluate the function at points that depend on the function and the resolution of your output device; you can't just evaluate the function at n points on the to be plotted range and expect to get an accurate plot.

For example, to plot sin(1/x) accurately, it must be evaluated many, many times near zero, but you do not want to do that further away from the origin, as it slows down plotting, and can produce less nice plots if you export to a vector format such as svg or postscript.