Experiment window run in the background

Hello, I builled an visual experiment, and every thing is working fine except one important thing - I want that the participant will press the Spcabar key in part of the trials; The problem is that the experiment window keep exit each time I press on the spacebar key, and continue running in the background... (if I go back to the experiment window it's still runnung but again exit from this window). It's write to me this error:

"Error using matlab.ui.Figure/get Invalid or deleted object."

"Error in TwoBack_finalll (line 74) h_but = get(hf,'CurrentCharacter')";

what this means? in other experiment code this function work excelent... :( and what should I do about it??

Thank you, Rotem.

Answer 1

[Walter Roberson]

I suspect that you are trying to get the current character of an axes but I suspect that you are using imshow. imshow tends to delete the axes.

Source code would help.

Answer 2

[Rotem Maymon]

Hello,

I'm not using imshow... here his my code - if you can see something wrong it's would be great... thank you!

clear all
clc

hf=figure('Toolbar','none','Menubar','none','NumberTitle','off',...
    'Units','normalized','position',[0 0 1 1],'Color',[1 1 1]);
fig_text1 = text(0.4, 0.8, 'Instructions');
fig_text2 = text(0.3, 0.7, 'In this experience you will see a sequence of letters');
fig_text3 = text(0.2, 0.6, 'Press the SPACE bar if the letter you see is similar to the one you saw TWO triels before');
fig_text4 = text(0.33, 0.4, 'Press any key when you are ready to start');
axis off

waitforbuttonpress
close(hf);

NumberOfTrails = 100; 
NumberOfResponses = NumberOfTrails;
NumberOfTwoSteps = 20;
Letters = ['A' 'B' 'C' 'D' 'E' 'F' 'G' 'H' 'I' 'J'];
VisualLetters = [];
IsTwoStep = ['0', '0'];
OneStepBack = Letters(end, randperm(size(Letters, 2), 1));
TwoStepBack = Letters(end, randperm(size(Letters, 2), 1));
VisualLetters{1} = OneStepBack;
VisualLetters{2} = TwoStepBack;

for counter = 3:NumberOfTrails 
    Random_number = rand(1,1);
    PercentageOfTrailsLeft = NumberOfTwoSteps / NumberOfTrails;
    if(PercentageOfTrailsLeft > Random_number)
        IsTwoStep(counter) = '1'; 
        NumberOfTwoSteps = NumberOfTwoSteps - 1;
        CurrentStep = TwoStepBack;
        VisualLetters(counter) = cellstr(CurrentStep);
        TwoStepBack = OneStepBack;
        OneStepBack = CurrentStep;
    else
        IsTwoStep(counter) = '0';
        CurrentStep = Letters(end, randperm(size(Letters, 2), 1));
        while(CurrentStep == TwoStepBack)
            CurrentStep = Letters(end, randperm(size(Letters, 2), 1));
        end
        VisualLetters(counter) = cellstr(CurrentStep);
        TwoStepBack = OneStepBack;
        OneStepBack = CurrentStep;
    end
    NumberOfTrails = NumberOfTrails - 1;
end

Responses = NaN(NumberOfResponses, 4);
hf=figure('Toolbar','none','Menubar','none','NumberTitle','off',...
    'Units','normalized','position',[0 0 1 1],'Color',[1 1 1]);

for Respone = 1:NumberOfResponses
    tic;
    axis off;
    text(0.5,0.5,VisualLetters(Respone));
    pause (750/1000); %750 ms
    clf;
    h_but = get(hf,'CurrentCharacter');
    ReactionTime = toc;
    Responses(Respone, 2) = VisualLetters{Respone} - 64;
    Responses(Respone, 3) = IsTwoStep(Respone) - 48;
    if ReactionTime < 0.75
        Responses(Respone, 4) = ReactionTime;
    end
    if Respone > 2
        if IsTwoStep(Respone) %if we got a twoStep
            if toc <0.75 %if we get a him to react show YES
                hold on;
                    text(0.5, 0.4, 'YES','Color','green','FontSize', 14);
                hold off;
            else %If not show NO
                hold on;
                    text(0.5, 0.4, 'No','Color','red','FontSize', 14);
                hold off;
            end
        %if it is not a two step and he prssed
        elseif isnan(Responses(Respone, 4)) && not(isTwoStep(Resone)) 
                hold on;
                    text(0.5, 0.4, 'No','Color','red','FontSize', 14);
                hold off;
        end
    end
    pause (50/1000); 
    if isnan(Responses(Respone, 4))
        Responses(Respone, 1) = 0;
    else
        Responses(Respone, 1) = 1;
    end

      clf(hf);
  end

close(hf)

[Walter Roberson]

I am not sure at the moment, but I recommend that you have a look at my responses in https://www.mathworks.com/matlabcentral/answers/?term=tag%3A%22always+parent%22

Answer 3

[Rotem Maymon]

Hello, Thank you. I've read this responses, and it's no it... :(

Have a good day.

[Walter Roberson]

Please post the modified version of your code that takes care to parent every graphics operation. (No point in my duplicating that effort.)