Hello Niklas
One way to adjust it is by normalizing the gradient vectors before plotting them.
Here's an updated version of your code:
f2 = @(x,y) 1./sqrt(x.^2+y.^2);
[u2,v2] = meshgrid(-1:0.01:1);
[du2,dv2] = gradient(f2(u2,v2));
% Normalize the gradient vectors
norm = sqrt(du2.^2+dv2.^2);
du2_norm = du2./norm;
dv2_norm = dv2./norm;
s = surf(u2,v2,f2(u2,v2));
hold on
contour(u2,v2,f2(u2,v2))
hold on
quiver(u2,v2,du2_norm,dv2_norm,'LineWidth',2)
axis([-1 1 -1 1 0 10])
caxis([0,10])
colormap(cool)
alpha(s,0.95)
shading flat
This code normalizes the gradient vectors by dividing the du2 and dv2 components by their magnitude (norm). This ensures that the length of each vector is 1, making them visible in the plot.
