MATLAB: Keep existing subplots while running code multiple times

Question

Hello,

I have written a code which calculates certain parameters and plots several subplots in a figure as follows:

figure('name','my_title');
h1=subplot(2,2,1);
plot (x1,y1);
h1=subplot(2,2,2);
plot(x2,y2);
h1=subplot(2,2,3);
plot(x3,y3);
h1=subplot(2,2,4);
plot(x4,y4);

Now I have to run the same code multile times for differnet data sets. I would like to keep the existing subplots (from lets say data set 1) and plot the new subplots (from lets say data set 2) on top of the existing subplots for comparison. But everytime I try to do it, its erasing the existing subplots and only plotting the current data set.

I tried to use findobj to check whether the figure exists and if so then use it as follows:

fOp.figName='my_title';
hf=findobj('Type','figure');
if ~isempty(hf)
    figure(hf);hold all;
else
     hf = figure('Name',fOp.figName);
     hold all;
end
h1=subplot(2,2,1);
hold all;
plot (x1,y1);
h1=subplot(2,2,2);
hold all;
plot(x2,y2);
h1=subplot(2,2,3);
hold all;
plot(x3,y3);
h1=subplot(2,2,4);
hold all;
plot(x4,y4);

While it keeps the figure 1 open for the multiple runs, but it still erases the previous subplots inside the figure 1. I think I have to use 'Children' function in some way but not sure how. Any help would be much appreciated. Thank you.

Answer 1

You can change your code as follows.

fOp.figName='my_title';
hf = findobj('Type','figure','Name',fOp.figName);
if ~isempty(hf)
    % get the handles if the figure already exist
    hf = figure(hf);
    h1 = hf.Children(4); % subplot 221
    h2 = hf.Children(3); % subplot 222
    h3 = hf.Children(2); % subplot 223
    h4 = hf.Children(1); % subplot 224
else
    % create figure and subplots if the figure does not exist
    hf = figure('Name',fOp.figName);
    h1=subplot(2,2,1);
    h2=subplot(2,2,2);
    h3=subplot(2,2,3);
    h4=subplot(2,2,4);
end
hold(h1,'on');
plot(h1,x1,y1);
hold(h2,'on');
plot(h2,x2,y2);
hold(h3,'on');
plot(h3,x3,y3);
hold(h4,'on');
plot(h4,x4,y4);