How to produce data randomly from a given matrix without changing the dimension

1 view (last 30 days)
I have some data for eg
A=[1;3;5;7;2]
Now i have to produced all these data randomly. Is there any matlab command to produce these data randomly without changing the dimension...Please help...

Accepted Answer

Jan
Jan on 6 Apr 2014
Edited: Jan on 6 Apr 2014
Perhaps you mean something like this:
A = [1;3;5;7;2]
for k = 1:10
A = A(randperm(length(A)))
end

More Answers (2)

Image Analyst
Image Analyst on 6 Apr 2014
Yes. It's a 5 row column vector. Of course it's possible to produce it, it just depends on what you mean by randomly. Do you just want to keep using randi(7,5) until your number match those? Like this:
A=[1;3;5;7;2]
% Use a Monte Carlo approach to generate A randomly
count = 1;
while count < 10000000
rv = randi(7, [5, 1]);
difference = abs(rv-A);
if max(difference) == 0
break;
end
count = count + 1;
end
message = sprintf('Found it after %d iterations', count);
uiwait(helpdlg(message));
Please clarify.
  2 Comments
Tinkul
Tinkul on 6 Apr 2014
Suppose A=[1;3;5;7;2] I mentioned randomly, which means
A1=[1;7;3;5;2] or A1=[2;5;1;3;7] etc.etc.. That means the row of A1 matrix have the value which is also in A but in different row.
Image Analyst
Image Analyst on 7 Apr 2014
This would have been helpful to include in your original post, don't you think? But it looks like Jan's code does what you want.

Sign in to comment.


Jos (10584)
Jos (10584) on 7 Apr 2014
Do you want a random permutation or a random derangement (i.e., none of the elements stays in place, as suggested by your comment to Image Analyst)?
% random permutation
B = A(randperm(numel(A))
% random derangement
B = A ;
if numel(A)>1
while any(B==A) % a rejection method
B = A(randperm(numel(A)) ;
end
else
disp('No derangement possible.')
end

Categories

Find more on Random Number Generation in Help Center and File Exchange

Tags

No tags entered yet.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!