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Create a random Matrix

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Maurizio
Maurizio am 24 Okt. 2011
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 Kommentare
Jan
Jan am 24 Okt. 2011
"I have a 8 column vector" sounds like a single vector. But "from each vector" might mean n vectors. Confusing.
Maurizio
Maurizio am 24 Okt. 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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Akzeptierte Antwort

Andrei Bobrov
Andrei Bobrov am 24 Okt. 2011
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 Kommentare
Jan
Jan am 31 Okt. 2011
@Maurizio: Accepting an answer means, that it solves your problem sufficiently.
Maurizio
Maurizio am 31 Okt. 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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Weitere Antworten (1)

Walter Roberson
Walter Roberson am 24 Okt. 2011
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 Kommentare
Maurizio
Maurizio am 30 Okt. 2011
Can you help me what I need to write on the for loop please?
Walter Roberson
Walter Roberson am 30 Okt. 2011
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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