%make a tabulated angle_cosinesquared potential

howmany=1000
k=10
phi0=pi/2
phi=0:pi/howmany:pi';
V=0.5*k*(cos(phi)-cos(phi0)).^2;
F=-k*sin(phi).*(cos(phi0)-cos(phi));
plot(phi,V,phi,F)
data(:,1)=phi;
data(:,2)=F;
data(:,3)=V;