how do i shuffle my stimuli so a, b, c, d or e could be asked in any random order?

Hello I am trying to use 'shuffle' to produce my stimuli randomly but have not been able to figure this out yet. Any help would be greatly appreciated!!

a = randperm(10, 5)-1

for k=1:length(a)

clf;text(0.5,0.5, num2str(a(k)),'FontSize',75);axis off;

pause(1)

clf; 

end
for x1 = randsample(a,1), pause(2)

   clf;text(0.5,0.5, num2str(x1),'Fontsize',75);axis off
  end
  pause(3)
  b = randperm(10, 4)-1
  for k=1:length(b) 
      clf;text(0.5,0.5, num2str(b(k)),'FontSize',75);axis off;
      pause(1)
      clf;
  end
  for x2 = randsample(b,1), pause(2)
      clf;text(0.5,0.5, num2str(x2),'FontSize',75);axis off;
  end
  pause(3)
  c = randperm(10, 3)-1
  for k=1:length(c)
      clf;text(0.5,0.5, num2str(c(k)),'FontSize',75);axis off;
      pause(1)
      clf;
  end
  for x3 = randsample(c,1), pause(2)
      clf;text(0.5,0.5, num2str(x3),'FontSize',75);axis off;
  end
  pause(3)
  d = randperm(10, 2)-1
  for k=1:length(d)
      clf;text(0.5,0.5, num2str(d(k)),'FontSize',75);axis off;
      pause(1)
      clf;
  end
  for x4 = randsample(d,1), pause(2)
      clf;text(0.5,0.5, num2str(x4),'FontSize',75);axis off;
  end
  pause(3)
  e = randperm(10, 1)-1
  for k=1:length(e)
      clf;text(0.5,0.5, num2str(e(k)),'FontSize',75);axis off;
      pause(1)
      clf;
  end
  for x5 = randsample(e,1), pause(2);
      clf;text(0.5,0.5, num2str(x5),'FontSize',75);axis off;
  end

[Jan]

What exactly is the problem? Which detail is not solved sufficiently by the posted code? What does "produce my stimuli randomly" mean? What is "shuffle" exactly?

[Michael Davies]

Hi, the script works fine but i need insert shuffle at the start somewhere so that it may prodcuce the variable c first or e. Right now it produces the stimuli in the order it is written and as i need to run it randomly many times this procedure wont work without it being shuffled.

Mike

[Stephen23]

• Copy-and-pasting code is a sign that you are doing something wrong. Use a loop instead.
• Creating lots of sequential variables a, b, c, etc just makes your code more complex, and the data harder to work with.

You need to:

• Put that data into one array (which could be numeric, cell , structure, table, etc) and then suddenly your task is much simpler because you can trivially use indexing.
• use randperm and a loop to run that code with a random order of data.

Read this too, if you want to avoid writing slow, inefficient, ugly code:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[Michael Davies]

Thank you for your advice!