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I want the code to randomize the rows and present each row for 10 times

Asked by bhagya lakshmi on 24 Aug 2019 at 4:37
Latest activity Edited by Walter Roberson
on 24 Aug 2019 at 15:48
I want the code to randomize the rows and present the stimulus by taking the each row values for 10 times. Here is the code that I have written.
Decentration = [0, 0.5; 0, 0; 0, -0.5; -0.5,0; 0.5, 0];
trial = 10;
for i = 1:trial;
for iter= 1:length(Decentration);
Decentration = Shuffle(Decentration, 2);
XDecentration = Decentration(:,1);
YDecentration = Decentration(:,2);
this presents the stimulus for 50 times but in a different proportion.
Please suggest a code for presenting each row of Decentation to be selected 10 times.

  1 Comment

Can you explain more?
You have Decentration = [0, 0.5; 0, 0; 0, -0.5; -0.5,0; 0.5, 0]; data,
you expectation from the Decentration matrix data?

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3 Answers

Answer by Walter Roberson
on 24 Aug 2019 at 8:08
 Accepted Answer

Decentration = [0, 0.5; 0, 0; 0, -0.5; -0.5,0; 0.5, 0];
trial = 10;
n = size(Decentration, 1);
idx = repmat(1:n, 1, trial);
order = randperm(size(idx,2));
randrows = Decentration(order,:);
XDecentration = randrows(:,1);
YDecentration = randrows(:2);
This code will present each row exactly trial times, but not in groups. For example, the second row might happen to occur twice in the first 10 stimuli. Or occur 10 times even (though that is not likely)
This is not the code to present each stimuli exactly once per trial: it is code that preserves the correct portions of entries over the entire experiment but not in the short term.

  2 Comments

This code gives error.
Index exceeds matrix dimensions.
Error in Disp_InvGabor (line 77)
randrows = Decentration(order,:);
randrows = Decentration(idx(order),:);

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Answer by KALYAN ACHARJYA on 24 Aug 2019 at 6:58
Edited by KALYAN ACHARJYA on 24 Aug 2019 at 6:59

Is this?
decentration = [0, 0.5; 0, 0; 0, -0.5; -0.5,0; 0.5, 0];
random_data=decentration(randperm(size(decentration, 1)),:);
[rows colm]=size(random_data);
trial = 10;
decentration_data=cell(rows,trial);
for i=1:rows
for j=1:trial
decentration_data{i,j}=random_data(i,:);
% I assume you have some process here, like apply stimulus to respective rows
end
end

  5 Comments

The above would present the data in a random order 10 times, but always the same order. It will also present the data in groups of 5, using all of the rows within each group.
Thank you so much.
It works. But it presents the selected random_data 10 times continuously. I also want this to be random
trial=randi(10);
% This generages the random trial number (maximum 10), change it accordingly
Like
trial=randi(maximum_allowable_trail_number);
%....................^^ enter any max number here
Check here examples
>> trail=randi(20)
trail =
16
>> trail=randi(20)
trail =
7
>> trail=randi(20)
trail =
11
Good Wishes!

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Answer by Bruno Luong
on 24 Aug 2019 at 8:04
Edited by Bruno Luong
on 24 Aug 2019 at 8:10

The array B of the below has exactly 10 times each row of A in random order:
m = size(A,1);
B = A(mod(randperm(10*m),m)+1,:);

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