Error using handle.handle/set

Hello,

I am trying to run this code, but I keep getting error

I am trying to have a patch updating on a background plot.

clear;clc;close all;

h.xt=patch(0,0,'b','erasemode','xor'); 
h.pth= plot(0,0,'k','markersize',2,'erasemode','background');

wp=[5 1;6 2;7 3]
veh=[0 -4 -4;0 -2 2];

set(h.pth,'xdata',wp(:,1),'ydata',wp(:,2),'Marker','o')
set(h.xt,'xdata',veh(1,:),'ydata',veh(2,:))

Answer 1

[Guillaume]

plot deletes the previous content of the figure, unless you use hold on, hence your patch handle becomes invalid as soon as you create the plot. To fix:

h.xt=patch(0,0,'b','erasemode','xor'); 
hold on
h.pth= plot(0,0,'k','markersize',2,'erasemode','background');