Selecting data from a plot in a GUI

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Michael
Michael on 12 Jul 2011
Answered: Andy on 28 Jan 2015
I have a plot on my GUI and I want to select some points on this plot and save their coordinates to a variable. The variable would have rows containing each point and 2 columns for the x,y values for those points.
I have tried using the brush function to select the data and then save it to a variable, but that is giving me problems.
Any other ideas?
Thanks!

Answers (3)

Fangjun Jiang
Fangjun Jiang on 12 Jul 2011
plot(magic(5));
[x,y]=ginput
You can select multiple data points, Press return when you are done.
  3 Comments
Michael
Michael on 12 Jul 2011
That worked great. Thanks so much!

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Fangjun Jiang
Fangjun Jiang on 13 Jul 2011
Michael, I've been thinking about this problem. You can use Brush on your plot. Click the "Brush" icon, select a group of data points, then select the highlighted data point and right click, you can select "Create Variable" which then will ask you for a variable name. Or, you can select "Copy Data to Clipboard", then in the Command window, you can type MyData=clipboard('paste'). Does this satisfy your need, or you need more formal API to use the Brush functionality? There is a lead in this post but I have not found an API for Brush yet.

Andy
Andy on 28 Jan 2015
An excellent option is provided below:
hBrushLine = findall(gca,'tag','Brushing');
brushedData = get(hBrushLine, {'Xdata','Ydata'});
brushedIdx = ~isnan(brushedData{1});
brushedXData = brushedData{1}(brushedIdx);
brushedYData = brushedData{2}(brushedIdx);
% and similarly for ZData in 3D plots

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