# how to split a vector into small subvectors based on condition

조회 수: 14 (최근 30일)
Elysi Cochin . 2020년 3월 15일
댓글: Ameer Hamza . 2020년 3월 15일
how can i split a vector into smaller sub vectors, such that the sum of each vectors is less than N
N = 60
V = [30 35 24 15 14 48];
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Walter Roberson 2020년 3월 15일
Breaking up into individual elements satisfies the stated conditions. There are other solutions too, but the question does not prevent the algorithm from being lazy and not even trying a different solution.

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### 채택된 답변

Ameer Hamza 2020년 3월 15일
편집: Ameer Hamza 님. 2020년 3월 15일
From your other question: https://www.mathworks.com/matlabcentral/answers/510716-compute-from-a-set-of-parameters. I suspect that you want to find all distinct combination of elements where the sum is less than 60 while keeping the number of trips to a minimum. The following code will find an optimal solution; however, it will only work if the number of elements of V is small (say less than 20). The solution have exponential time and space complexity, so the required resources will grow very quickly. For large number of variables, I would recommend using some greedy method, which can give a sub-optimal solution.
N = 60;
V = [30 35 24 15 14 48];
a = mat2cell(repmat([0 1], numel(V), 1), ones(size(V)), 2);
combs = logical(combvec(a{:})'); % create all possible combinations
combs(1, :) = []; % remove a trivial combination
cost = sum(combs.*V, 2);
valid_index = cost < N;
valid_combs = combs(valid_index, :);
valid_costs = cost(valid_index);
[valid_costs, index] = sort(valid_costs, 'descend');
valid_combs = valid_combs(index, :);
optimal_combs = logical([]);
while ~isempty(valid_combs)
current_comb = valid_combs(1,:);
optimal_combs = [optimal_combs; current_comb];
index = any(valid_combs(:, current_comb) == valid_combs(1, current_comb), 2);
valid_combs(index, :) = [];
end
result = {};
for i=1:size(optimal_combs,1)
result{i} = V(optimal_combs(i,:));
end
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Ameer Hamza 2020년 3월 15일
No problem. Gald to be of help.

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### 추가 답변 (1개)

Ahmed Anas 2020년 3월 15일
편집: Ahmed Anas 님. 2020년 3월 15일
Dear, it will give you the desired results
clear all
clc
V = [30 35 24 15 14 48]
N=60
for i=1:size(V,2)
subsA = nchoosek(V,i);
for j=1:size(subsA)
Sum=sum(subsA(j,:));
if Sum<N
G=subsA(j,:)
end
end
end
##### 댓글 수: 3표시 이전 댓글 수: 2숨기기 이전 댓글 수: 2
Elysi Cochin 2020년 3월 15일
sir, i executed the code, its somewhat close,
i dont want repeatition of elements, once if i store a value into a new subvector , then i wont consider that value
my expected output is
{ [ 30 15 14] [ 35 24 ] [ 48] }

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