Create a random Matrix

I have a 8 column vector n*1. Can I create a Random matrix of n*8?
The function must take one value from each vector and create a matrix with 8 columns and n rows.
Please help me :-)

2 Comments

Jan
Jan on 24 Oct 2011
"I have a 8 column vector" sounds like a single vector. But "from each vector" might mean n vectors. Confusing.
Maurizio
Maurizio on 24 Oct 2011
I have 8 different variable. Each variable is a column vector (nx1).
What I need is to have as OUT a random matrix with 8 column and n rows. The value on the first OUT Column must be only the value of the first IN column

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 Accepted Answer

A1,A2,..,A8 - your vectors (nx1), let n = 5;
for j1 = 1:8, eval([sprintf('A%d',j1),'=randi(20,5,1)']); end
A = eval(['[',sprintf('A%d,',1:8),']'])
out=A(bsxfun(@plus,cell2mat(arrayfun(@(x)randperm(n)',(1:8),'un',0)),(0:7)*n))

3 Comments

Maurizio
Maurizio on 24 Oct 2011
Thanks andrei, the problem that the OUT columns value on each columns must be the same of the IN columns. For example the values that I have on the third OUT column must be one of the third IN column.
Jan
Jan on 31 Oct 2011
@Maurizio: Accepting an answer means, that it solves your problem sufficiently.
Maurizio
Maurizio on 31 Oct 2011
@JAN: I accept but because create a random Matrix but as you can see from my comment Is that there was some problem about OUT columns values

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More Answers (1)

rv(:,1) = randomvector1;
rv(:,2) = randomvector2;
rv(:,3) = randomvector3;
....
rv(:,4) = randomvector4;
rants = zeros(8, n);
for K = 1:n
rants(:,K) = A Random Selection of One Entry Per Column from rv
end
How to do "A Random Selection of One Entry Per Column from rv" is left to you to work on in more detail. I will hint that it involves using rand().

3 Comments

Maurizio
Maurizio on 30 Oct 2011
Can you help me what I need to write on the for loop please?
Maurizio
Maurizio on 30 Oct 2011
Can you help me what I need to write on the for loop please?
floor(1 + n * rand())
will give you a random row number.
If I say much more than I will be completing your assignment for you.

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