Shuffle a vector of repeated numbers so the numbers do not repeat

Hi,

I have a vector fam1_1 = [1,1,1,2,2,2,3,3,3,4,4,4] that I need shuffled without having any numbers be repeated. Does anyone have any suggestions on how to do this?

[Image Analyst]

In general this is not possible. It's possible for that specific vector, but not in general for any arbitrary vector. For example if fam1_1 were equal to [1,1,1,2,2,1,1,1,1,1,1] it would not be possible to shuffle without repeating a 1. Just want to make sure you realize that.

Answer 1

[Azzi Abdelmalek]

Edit

fam1_1 = [1,1,1,2,2,2,3,3,3,4,4,4] 
ii=unique(fam1_1)
n=numel(fam1_1)
m=numel(ii)
p=numel(fam1_1)/numel(ii)
x=ii(randperm(m))
out=x
for k=2:p
  y=setdiff(ii,x(end))    
  y1=y(randi(m-1))
  y2=setdiff(ii,y1)
  x=[y1 y2(randperm(m-1))]
  out=[out x]
end

[Yue Zhang]

the final output does not equal the length of my original vector

[Azzi Abdelmalek]

You said, the number have not to be repeated

[Yue Zhang]

sorry, repeated as in not the same number one after another.

[Azzi Abdelmalek]

Look at the edited answer

[Yue Zhang]

that works! thank you very much :)

Answer 2

[Image Analyst]

Like I said above, in general it's not possible, but it might be able to be solved for a particular sample. For the sample you gave, here's one solution that solves it in just 2 simple lines of code.:

fam1_1 = [1,1,1,2,2,2,3,3,3,4,4,4] % Original data
temp = reshape(fam1_1, [], 4)' % Reshape into 2D matrix
fam1_1 = temp(:)'  % Turn into column vector then transpose into row vector like the original.