4-class perceptron classification

Good evening, I hope everyone is well. I have a single-layer perceptron that is meant to take in two inputs and provide an output as one of four classifications. I then need to plot the inputs and the hyperplanes dividing the four classes. I'm getting errors when I try to run the code that I suspect are related to the number of outputs I'm trying to get. Here's the code I'm working with:

if true
   % Initialize the Input Space (extended input matrix)
   x = [1 1 1 2 2 -1 -2 -1 -2; 1 1 2 -1 0 2 1 -1 -2];

     % Initialize the extended target vector
     t = [0 1 1 2 2 3 3 4 4];

     % Plot the input locations
     figure
     hold on
     for i=1:length(x)
        if (t(i)==1)
            scatter(x(1,i), x(2,i),'k ', 'filled');
        elseif (t(i)==2)
            scatter(x(1,i), x(2,i),'r ', 'filled');
        elseif (t(i)==3)
            scatter(x(1,i), x(2,i),'b ', 'filled');
        elseif (t(i)==4)
            scatter(x(1,i), x(2,i),'g ', 'filled');
        end
     end
     grid on
     line([0 0], ylim, 'linewidth', 1);  %y-axis
     line(xlim, [0 0], 'linewidth', 1);  %x-axis
     legend('class_1', 'class_2', 'class_3', 'class_4')

     net = perceptron;
     net.trainparam.epochs = 100;    % Set # of training epochs
     net.trainparam.goal = 1e-2;     % Set desired max error
     net.trainparam.lr = 0.1;        % Set desired learning rate
     train(net, x, t);               % Train the perceptron
     predictions = net(x);           % Get data predictions

     net.IW{:};      % Learned weights
     net.b{:};       % Learned biases

     % Equation of a line: w1*x1 + w2*x2 + b = 0
     % Plot the lines 
     plot([-net.b{1}/net.IW{:}(1,1),0],[0,-net.b{1}/net.IW{:}(1,2)])
     plot([-net.b{2}/net.IW{:}(2,1),0],[0,-net.b{2}/net.IW{:}(2,2)])
     hold off;
  end

The trainparam epochs, goal and lr are initial conditions an can change but I don't think that's where the problem is.

I'd appreciate any help you're able to provide. Best regards.

[Greg Heath]

use length(t) not length(x)

point t = 0 is not plotted

what are your error messages?

[Bill Symolon]

Thanks, Greg. I figured out that I needed to use a second perceptron and two sets of targets to get the required output. The code is working now. Regards, Bill