how to create different column as a different vector from a matrix
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Hi, I am a new user of matlab. I am having a huge matrix (m,n)and I want to convert n different column vectors. How to do that? for example I am trying to do in following way
a=[1 2 3;4 5 6;7 8 9;10 11 12];
for i = 1 : size(a, 2)
qj = a(:,i)
end
but it is only storing last column . But I want to store like q1= 1 2 3 q2= 4 5 6
and so on please help me this regard. Thanks in advance.
Abhi
采纳的回答
Fangjun Jiang
2011-9-13
Don't use q1, q2, q3. Use the following. You can reference it using q{1},q{2},q{3}. Even further, q{1}(2), q{3}(4).
a=[1 2 3;4 5 6;7 8 9;10 11 12];
q=cell(size(a,2),1);
for i = 1 : size(a, 2)
q{i} = a(:,i);
end
8 个评论
Abhinav
2011-9-13
Fangjun Jiang
2011-9-13
You probably have q pre-defined. Do clear q first or better define q as an empty cell array first.
q=cell(size(a,2),1)
Fangjun Jiang
2011-9-13
The error is caused by something else. If you run clear q first and then run the above code. There shouldn't be any error.
Jan
2011-9-14
@Fangjun: Please insert the "q = cell(size(a, 2), 1)" code in your answer. Then I'll vote for it immediately.
Fangjun Jiang
2011-9-14
Hah, Jan! It looks like I've earned a vote. See my first comment. I'll also put it in the answer.
Abhinav
2011-9-15
Jan
2011-9-15
+1. The term "immediately" meant "as soon as I read it again".
Fangjun Jiang
2011-9-16
Go through the document, under MATLAB->Data Analysis, Graphics
更多回答（1 个）
Walter Roberson
2011-9-13
0 个投票
3 个评论
Abhinav
2011-9-14
Jan
2011-9-14
@Abhinav: The FAQ tells, that it is much more efficient to use the columns of a large array, that to split the array into vectors. Using variables called q1, q2, q3, ... will lead to problems and makes the code slow, hard to expand (if you need more vectors, you have to edit all occurences) and much harder to debug. Therefore it is recommended to use q(:,i) directly instead.
Please take into account, that this topic is included in the FAQ, because it leads to problems very frequently.
Abhinav
2011-9-15
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