# Dark artifacts in mathematica plot

When plotting in Mathematica I just got some "dark artifacts". Here is my code:

Plot3D[Exp[-100 x^2], {x, -5, 5}, {p, -5, 5}, PlotRange -> All, PlotPoints -> {100, 100}]


and the result is (I know that the 3D is useless here, but I minimized my actual code to the relevant problem). I have the feeling that it has something to do with the precision, when there is the transition from 10^-200 or so to 0 but increasing the WorkingPrecision didn't change anything.
I tried plotting in 2D from x = 2.3 and there is still an exponential function with value 10^-175 to see. When I plot from 3 to 4 (which is after the dark artifact line) then the 2D Plot says just zero.

I don't need to caluculate with super high precision, I just want to get rid of those dark strips.
I also tried to look for similar questions but couldnt find one, perhaps because I don't really know if artifacts is the right word.

• it's just fp noise. Try plotting Chop@Exp[-100 x^2] to get rid of them. – rm -rf Nov 10 '13 at 17:22

Chop is useful here:

You can use it inside the Plot3D (as rm -rf wrote in the comment) for rounding small values of Exp

Plot3D[Chop@Exp[-100 x^2], {x, -5, 5}, {p, -5, 5}, PlotRange -> All, PlotPoints -> 100]


If your function is complicated you can use Chop as the post-processing function

Chop@Plot3D[Exp[-100 x^2], {x, -5, 5}, {p, -5, 5}, PlotRange -> All, PlotPoints -> 100]


In the both cases results are the same: • thx to you, ybeltukov, and rm -rf. i appreciate the post-processing option :) – user104857 Nov 10 '13 at 18:29