A simple code can be used to depict the schematic diagram of the polymer network. (To solve the pain of manual depiction)

```
clc,clear,close all
N = 200; % The length of chains.
P = 200; % The amount of chains.
% Random starting points.
x = rand(P,1) * 120 - 60; % The size of the box.
y = rand(1,P) * 120 - 60;
for p = 1:P
xt = x(p);
yt = y(p);
for n = 1:N
xt(n+1) = xt(n) + sind(rand * 360); % Growth angle.
yt(n+1) = yt(n) + sind(rand * 360);
end
% Change the transperance of chains to show 2.5D effect.
plot(xt, yt, 'Color', [0, 0, 0, rand])
hold on
end
% Image properties.
xlim([-50 50])
ylim([-50 50])
xticks([])
yticks([])
axis square;
```

By simple modification, a stretched network could also be produced.