%%% vfd.m, script for vectorfields in plane
% rha, 01 mar 2004 on vaio
% this exm is from the parabolic umbilic
u = inline('4*x.^3 - 2*x', 'x', 'y')
v = inline('2*y', 'x', 'y')
x = linspace(-1,1,11);
y = linspace(-1,1,11);
[X,Y] = meshgrid(x,y);
U = u(X,Y); V = v(X,Y);
quiver(X,Y,U,V)
axis image