Create a random Matrix

2011 10 24
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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 :-)

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Jan
Jan 2011-10-24
"I have a 8 column vector" sounds like a single vector. But "from each vector" might mean n vectors. Confusing.
Maurizio
Maurizio 2011-10-24
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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Andrei Bobrov
Andrei Bobrov 2011-10-24

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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))

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Maurizio
Maurizio 2011-10-24
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 2011-10-31
@Maurizio: Accepting an answer means, that it solves your problem sufficiently.
Maurizio
Maurizio 2011-10-31
@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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Walter Roberson
Walter Roberson 2011-10-24

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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().

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Maurizio
Maurizio 2011-10-30
Can you help me what I need to write on the for loop please?
Maurizio
Maurizio 2011-10-30
Can you help me what I need to write on the for loop please?
Walter Roberson
Walter Roberson 2011-10-30
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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