# Mathematica exit when calling plot. Bug?

I'm currently studing the behaviour of some integral for which I cant find an analytic solution.

As this function depend on a vector on the unit sphere, I first defined it with 3 parameters before making a second one taking eulers angle and calling the first one.

However, when I try to plot my function I don't get my result. Either :

• I get my first graph, and the worksheet resets

• Mathematica exits

I'm using 9.0.1.0 on linux (Archlinux 3.13.6-1 x86_64)

Here is my worksheet

w[a_, b_, c_] :=
NIntegrate[(a x + b y + c) (x^2 + y^2 + 1)^(-2)*
HeavisideTheta[a x + b y + c], {x, -1, 1}, {y, -1, 1}]
w3D[theta_, phi_] :=
w[Sin[theta] Cos[phi], Sin[theta] Sin[phi], Cos[theta]]
w[0, 0, 1] + 4 w[0, 1, 0]

Plot[w3D[theta, 0], {theta, 0, Pi}]
Plot[w3D[theta, Pi/4], {theta, 0, Pi}]
Plot3D[w3D[theta, phi], {theta, 0, Pi}, {phi, 0, Pi/2}]


PrecisionGoal -> 10, AccuracyGoal -> 5

I mean the application vanish and I can't find it using ps -A It's strange since I happened to see my computer run for long minutes during complexe calculation. –  Amxx Mar 19 at 16:38