how to run a certain code loop for 'N' times and get 'N' number of output outside the loop.
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I have certain code which I run for 'N' times using 'for' loop but after running the loop when I want to get all the N value of the parameters, it only gives the Last (Nth) value. for example this code generates the five matrices if I put A inside.
clc clear all N = 5; for i = 1:N A = rand(3,5); A end
% output is
A =
0.4352 0.9375 0.5505 0.2475 0.3547
0.1577 0.1078 0.4274 0.4474 0.7731
0.6005 0.9000 0.1524 0.5328 0.8817
A =
0.7341 0.6411 0.3105 0.4269 0.9250
0.4064 0.1275 0.5786 0.0331 0.3583
0.6042 0.4962 0.9436 0.9294 0.2600
A =
0.7869 0.6848 0.9429 0.9094 0.6503
0.5116 0.0924 0.0966 0.0113 0.3851
0.5625 0.8726 0.8459 0.5237 0.6493
A =
0.7629 0.2782 0.6316 0.4008 0.0904
0.5757 0.8398 0.8335 0.5543 0.7444
0.6319 0.4268 0.2702 0.4439 0.0326
A =
0.4297 0.5223 0.8845 0.8946 0.5676
0.0373 0.9096 0.2550 0.3985 0.8945
0.9758 0.3832 0.9090 0.6250 0.2142
% If I put 'A' outside the loop it gives only the last (5th) value.
clc clear all N = 5; for i = 1:N A = rand(3,5); end A
A =
0.4297 0.5223 0.8845 0.8946 0.5676
0.0373 0.9096 0.2550 0.3985 0.8945
0.9758 0.3832 0.9090 0.6250 0.2142
I want all the five matrices outside the loop as A1, A2, A3,A4 and A5. Please help me.
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回答(3 个)
KSSV
2016-10-26
Make A a 3D matrix.
N = 5;
A = zeros(3,5,N) ;
for i = 1:N
A(:,:,i) = rand(3,5);
end
You can access A using A(:,:,i) where i = 1,2,3,4,5.
0 个评论
Thorsten
2016-10-27
You don't need the loop:
A = rand(3, 5, N);
3 个评论
Jan
2016-11-4
编辑:Jan
2016-11-4
@MANISH KUMAR: Please use the "{} Code" button to post readable code. Do not hide an important detail of the question in the comment of an answer, but all required details shsould be found inside the original question. Therefore use the possibility to edit the question. Thanks.
You got several suggestion already. All you have to do is storing the matrix in each iteration.
Result = cell(1, N);
for i = 1:N
...
ResultC{i} = X;
end
...
% Perhaps:
ResultM = cat(3, ResultC{:});
Stefano Gianoli
2016-10-26
编辑:Stefano Gianoli
2017-7-26
You might allocate the memory required for A so it can hold 3 x 5 x N elements instead of just 3 x 5:
>>N = 5; for i = 1:N A(:,:,i) = rand(3,5); end, A
A(:,:,1) =
0.8147 0.9134 0.2785 0.9649 0.9572
0.9058 0.6324 0.5469 0.1576 0.4854
0.1270 0.0975 0.9575 0.9706 0.8003
A(:,:,2) =
0.1419 0.7922 0.0357 0.6787 0.3922
0.4218 0.9595 0.8491 0.7577 0.6555
0.9157 0.6557 0.9340 0.7431 0.1712
A(:,:,3) =
0.7060 0.0462 0.6948 0.0344 0.7655
0.0318 0.0971 0.3171 0.4387 0.7952
0.2769 0.8235 0.9502 0.3816 0.1869
A(:,:,4) =
0.4898 0.7094 0.6797 0.1190 0.3404
0.4456 0.7547 0.6551 0.4984 0.5853
0.6463 0.2760 0.1626 0.9597 0.2238
A(:,:,5) =
0.7513 0.6991 0.5472 0.2575 0.8143
0.2551 0.8909 0.1386 0.8407 0.2435
0.5060 0.9593 0.1493 0.2543 0.9293
you might also preallocate A for speed:
>> A = zeros(3,5,N);
2 个评论
KSSV
2016-10-26
N = 5; for i = 1:N, eval(sprintf('A%i = rand(3,5);A%i',i,i)), end
This is not suggested.
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