Replot a matlab.graphics.chart

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JB
JB on 6 Sep 2017
Commented: JB on 6 Sep 2017
I have a simple issue that I could use some help with. I am preparing a loop where each cycle saves a plot in a matlab.graphics.chart. A simple code example:
x=[2 4 6 8];
y=[10 20 30 40];
plot1=plot(x,y);
How do I re-plot "plot1"? Thanks
  7 Comments
JB
JB on 6 Sep 2017
Here is an example:
x=[2 4 6 8; 3 6 9 12; 0 -2 -4 -6];
y=[10 20 30 40; 10 20 30 40; 10 20 30 40];
for K = 1 : 3
hold on
Plot=plot(x(K,:),y(K,:));
plotdata{K,1}=Plot;
end
Then I want to be able to call and plot one of the three generated plots in the "plotdata"

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Accepted Answer

Guillaume
Guillaume on 6 Sep 2017
JB, looking at the various comments in this question, I've got the feeling that you're not totally understand what it is that the plot function returns.
The plot function returns a handle to a line object (which you store in your plotdata variable in one of your comment). Now one of two things can happen:
  • that line object still exists in the figure: In that case, you can toggle its visibility, change its properties (colour, line style, etc.) or do all sorts of things with it, but in any case, it is still part of whichever figure you created it in.
  • that line object no longer exists, for example the figure has been closed or the plot was deleted because you plotted on the same figure without hold on. In that case, the handle that you've stored in your variable is no longer valid. It does not contain any information about the original plot. It's completely useless and there is no way to retrieve the original plot.
This is why your question is confusing. Either the plot still exists (it may be hidden), in which case there's nothing to do to replot (except maybe unhide the plot), or the plot no longer exists in which case what you've stored is now useless and you'll have to call the plot function to replot
  1 Comment
JB
JB on 6 Sep 2017
Hi Guillaume. You are absolutely right, it is my lack of matlab knowledge which makes it confusing. I thought that I could prepare each plot during the loop function and then call it later. Thanks a lot for the plot description.

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More Answers (2)

KL
KL on 6 Sep 2017
Edited: KL on 6 Sep 2017
plot1 is the axis handle. "re-plotting" means plotting on the same figure window with the new data.
for iCount = 1:5
x = iCount*[2 4 6 8];
y = iCount*[10 20 30 40];
h1 = figure(1); %h1 is figure handle
plot1=plot(x,y); %plot1 is axis handle
end
If you want to retain the plot from previous loop, use hold on at the end of for loop
  2 Comments
JB
JB on 6 Sep 2017
Here is an example for three plots:
x=[2 4 6 8; 3 6 9 12; 0 -2 -4 -6];
y=[10 20 30 40; 10 20 30 40; 10 20 30 40];
for K = 1 : 3
hold on
Plot=plot(x(K,:),y(K,:));
plotdata{K,1}=Plot;
end
From this I want to be able to call one of the plots from the plotdata array and re-plot it. In my original array I have 60 different plots. Is it possible?

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José-Luis
José-Luis on 6 Sep 2017
Not sure this is what you mean:
numPlots = 10;
lH = cell(1,numPlots);
for ii = 1:numPlots
hold on;
lH{ii} = plot(rand(10,1));
lH{ii}.Visible = 'off';
end
lH{2}.Visible = 'on';
  3 Comments
JB
JB on 6 Sep 2017
The overall goal is to have the user of the GUI to load a relatively large dataset by uigetfile. Then from a pushbutton the data will be loaded and a data array is generated from a loop function where one part of the stored data is the 60 times plot data. Then from the GUI the user should be able to call a specific plot by a checkmark activation. So if I can just either re-plot the stored data or put a specific handle on each plot then it should be possible.

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