Extract scattered data from fig

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mariana mahamud
mariana mahamud on 13 May 2019
Commented: Adam Danz on 14 May 2019
I want to extract data from a lot of graph fig files. My data are consist of scattered points in a graph. I used the code below however there is nothing in the x and y variables. How to fix this?
clc
clear all
addpath(genpath('PIV TEST 2'))
for k = 2:21
h = openfig(sprintf('%d.fig',k));
h = findobj(gca,'Type','line');
x = get(h,sprintf( 'XData',k));
y = get(h, sprintf('YData',k));
end
Is there anything wrong in my coding?
a.png
  2 Comments
Adam Danz
Adam Danz on 13 May 2019
Are the figures opening? Do you get any error or warning messages? Have you tried running the loop through manually and looking at what happens on each line? What have you done so far in the problem solving phase?
These two lines are definitely wrong.
x = get(h,sprintf( 'XData',k)); % should be get(h, 'XData')
y = get(h, sprintf('YData',k)); % same
Also, you're not storing the loop variables anywhere. They are being overwritten on each loop.
Lots of stuff to fix here.
mariana mahamud
mariana mahamud on 14 May 2019
Thank you sir for pointing out my mistake in the loop there was no error at all, all the figures appear well, its the same for manually and loop. The figures shows up like the image i attached but there is no data in the variables

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Accepted Answer

Adam Danz
Adam Danz on 14 May 2019
Edited: Adam Danz on 14 May 2019
Here is a cleaned-up version of your code that finds any and all objects in the specified figure that contain an "XData" property. It will work no matter how the plots were produced (line, scatter, etc).
I suggest storing the (x,y) values in a cell array.
x = cell(20,1);
y = x;
for k = 2:21
fh = openfig(sprintf('%d.fig',k));
h = findobj(fh,'-Property', 'XData'); %any object with property "XData" on figure fh
x{k} = get(h,'XData');
y{k} = get(h,'YData');
end
If more than one object was located, x and y will be a cell array containing one element for each object.
  2 Comments
mariana mahamud
mariana mahamud on 14 May 2019
I tried this and it works! thank you so much sir!
Adam Danz
Adam Danz on 14 May 2019
Glad I could help.

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