Save two variables generated within a for loop

Hi. I am trying to save the two variables (x_out and y_out) present in the for loop (see inside the function 'example.m', line 34 and 35).

How can I do this?

Attached you will find the .txt files to use the function.

X = importdata('X.txt');
IDX = importdata('IDX.txt');

example(X, IDX);

Answer 1

[Zahrah Walid]

Variables generated inside a function are locl variables inside the function only.

you can return the wanted variables from your function as follows:

function [x_out, y_out]=example(X, IDX)
%your function body as you provide
end

and when calling the function from the main program, you just put x_out and y_out values in your wanted variable in main program, i.e.:

X = importdata('X.txt');
IDX = importdata('IDX.txt');

[x,y] = example(X, IDX); %your x_out value is assigned into x variable and y_out value is assigned into y variable.

[Alberto Acri]

Thank you for your answer @Zahrah Walid, but I knew that.

I meant something like shown in the second plotted figure.

I modified the example.m function and added these lines of code.

X = importdata('X.txt');
IDX = importdata('IDX.txt');

%example(X, IDX);
[px, py] = example(X, IDX);

figure()
plot(px,py,'*k');   % I want to get the second figure but with all the * blacks (as in the first plotted figure)
xlim([70 430])
ylim([150 300])

[Zahrah Walid]

You just have to define px and py as follows in the function:

px(i+1,k) = x_out;
py(i+1,k) = y_out;

It's preferred to setup the second figure by the same settings of the first one to avoid pseudo differences.

figure()
plot(px,py,'*k');   % I want to get the second figure but with all the * blacks (as in the first plotted figure)
axis equal; %to be the same ratio
xlim([70 430])
ylim([150 300])

and this is the whole code, I have tried it after modification and I think it works as you want:

X = importdata('X.txt');
IDX = importdata('IDX.txt');
%example(X, IDX);
[px, py] = example(X, IDX);
figure()
plot(px,py,'*k');   % I want to get the second figure but with all the * blacks (as in the first plotted figure)
axis equal;
xlim([70 430])
ylim([150 300])


function [px, py] = example(X, IDX)

    k=max(IDX);

    Colors=hsv(k);

    Legends = {};
    n = 1;
    for i=0:k
        Xi=X(IDX==i,:);
        if i~=0
            Style = 'x';
            MarkerSize = 8;
            Color = Colors(i,:);
            % Legends{2*n-1} = ['Cluster #' num2str(i)];
            % Legends{2*n} = ['Boundary # ' num2str(i)];
            n = n+1;
            
        else
            Style = 'o';
            MarkerSize = 6;
            Color = [0 0 0];
            if ~isempty(Xi)
                Legends{end+1} = 'Noise';
            end
        end
        if ~isempty(Xi)
            x_temp = Xi(:,1);
            y_temp = Xi(:,2);

            s = 1;
            k = boundary(x_temp,y_temp,s);
            x_out = x_temp(k);
            y_out = y_temp(k);
            px(i+1,k) = x_out;
            py(i+1,k) = y_out;
            plot(x_temp,y_temp,Style,'MarkerSize',MarkerSize,'Color',Color);
            hold on
            plot(x_out,y_out,'*k');
            hold on
                                  
        end
        hold on;
    end
    hold off;
    axis equal;
    grid on;
    legend(Legends);
    legend('Location', 'NorthEastOutside');
    xlim([70 430])
    ylim([150 300])

end

figure 1

figure 2

Is this what you want?

[Alberto Acri]

Yes exactly!