MATLAB Answers

Nancy
0

Splitting 1 column array

Asked by Nancy
on 15 Aug 2012
Hi all,
I have various column matrices with varying number of elements from 38-202. I want to split each matrix into 5 small matrices each containing the same number of elements. The distribution of numbers into each can be random. If the original matrix has more elements, some can be ignored as well. Like for example if the original matrix has 204 elements and I want to split it into 5 matrices. So only 200 elements can be shuffled and 4 need to be ignored.
Is there any function in MATLAB I can use?
Nancy

  1 Comment

Azzi Abdelmalek
on 15 Aug 2012
are the matrix square?

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2 Answers

Walter Roberson
Answer by Walter Roberson
on 16 Aug 2012
 Accepted Answer

num_subsets = 5;
matlen = length(YourVector);
num_to_use = matlen - mod( matlen, num_subsets );
idx = randperm(matlen);
shuffled = YourVector(idx(1:num_to_use));
subsets = reshape(shuffled, [], num_subsets);
The subsets would then be the columns.

  3 Comments

Azzi Abdelmalek
on 16 Aug 2012
the result is one matrix
Walter Roberson
on 16 Aug 2012
Yes, but I did indicate that the subsets would be the columns. Splitting into individual matrices is usually not a good idea in this kind of situation.
Nancy
on 16 Aug 2012
Works perfectly. Thanks Walter :)

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Azzi Abdelmalek
Answer by Azzi Abdelmalek
on 15 Aug 2012

example
A=rand(102,2);B=A(1:100,:)
result=reshape(B,5,8,5)

  1 Comment

Walter Roberson
on 16 Aug 2012
Not quite, as that does not do any shuffling.

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