Can I extract XY data from a figure and sort it by the color of the datapoints?

I have a figure that is shown below, where the data is either red or blue. I need to extract the XY data from this figure and seperate the red data from the blue data. Is there a piece of MATLAB code that can extract just the data that corresponds to a certain property of the datapoints? While its hard to notice in the image, the circles representing the red data are also a different size from the blue data, so I could sort them by size too if it's easier.

[KSSV]

What image you have? .png or .tif or .fig?

[Jacob Blumeier]

It's a .fig file, but i also have a .jpg of it too.

[Image Analyst]

Why don't you have the original data that you used to plot it anymore???

[Jacob Blumeier]

It was an oversight on my part. The code I edited and used from my professor simulated particles in a rotatating fluid, and in his original simulation all of the particle locations were the same size. Because of that he just compiled all of the data into a text file. For my simulation I used particles of two different sizes and I kept it the same so that it goes to a text file, and all of the datapoints are jumbled together in that text file.

In short, I'm new to MATLAB and have no clue what I'm doing.

[KSSV]

You have to use some thing like this: https://in.mathworks.com/help/matlab/ref/allchild.html

Answer 1

[Amrtanshu Raj]

Hi,

Since you have a .fig file, the following code will help you get back the datapoints. This is the basic structure, you may have to tweak it a little based on the original method used to plot it.

%lets say your figure is name fig2dataset.fig
fig = openfig('fig2dataset.fig'); %load the figure back to matlab
k = fig.Children.Children; %get the children of the figure file ie. the datapoints
for i = 1:size(k,1) %itterate to all the lines plotted
    disp("Dataset"+i); 
    for j = 1:length(k(i).XData)
        disp([k(i).XData(j) k(i).YData(j)])%disp the X and Y data points
    end
end