Plot a Line of best fit onto a previously made graph that contains subplots

I graph stress vs strain earlier in my code just to verify the data looks good, later on I want to add a line of best fit over the small linear region before failure onto either the same figure or a new figure (either way I want to have stress vs strain and the corresponding line of best fit on one graph).

%% Graph Stress vs Strain

figure(2)
for k=1:n
    subplot(1,n,k)
    x = epsilon{1,k};
    y = sigma{1,k};
    plot(x,y,'.')
    title('Stress vs Strain'),xlabel('Strain (%)','FontWeight','bold'),ylabel('Stress (MPa)','FontWeight','bold')
end

Above is the code for the stress vs strain graph

below is the code i currently have to try to graph the line of best fit on the same figure

figure(2)
for k=1:n
    x =  cut_epsilon{1,k}(1:end,1);
    hold on
    subplot(1,n,k)
    plot(x, (slope(k)*x+intercept(k)), 'color','magenta' )
    hold off
end

[Dyuman Joshi]

"(either way I want to have stress vs strain and the corresponding line of best fit on one graph)"

Why not merge the two for loops together?

Answer 1

[Cris LaPierre]

You must make the axes current first, then turn hold on.

subplot(m,n,p) ... If axes exist in the specified position, then this command makes the axes the current axes.

Try modifying the code in your second loop to this (untested)

figure(2)
for k=1:n
    x =  cut_epsilon{1,k}(1:end,1);
    subplot(1,n,k)
    hold on
    plot(x, (slope(k)*x+intercept(k)), 'color','magenta' )
    hold off
end