Elegant / Vectorized way of getting array from start_index vector and end_index vector?

Question

Evan 2013-3-16

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Hello

Suppose start_index = [1 5 10]; and end_index = [3 8 12];

Is there an elegant solution to get an output of [1 2 3 5 6 7 8 10 11 12], that is the function takes each start value and gives all inclusive values between the start and end value, repeats with the next index, until all inclusive values are included in a single output vector?

Thank you

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Answer 1

Azzi Abdelmalek 2013-3-16

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https://ww2.mathworks.cn/matlabcentral/answers/67426-elegant-vectorized-way-of-getting-array-from-start_index-vector-and-end_index-vector#answer_78839

编辑：Azzi Abdelmalek 2013-3-16

在 MATLAB Online 中打开

EDIT

v=[1 2 3 5 6 7 8 10 11 12]
start_index = [1 5 10]; 
end_index = [3 8 12];
out=cell2mat(arrayfun(@(x,y) x:y,start_index, end_index,'un',0))
out=intersect(out,v)

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Evan 2013-3-16

Lines 2~4 were what I needed. Brilliant, exactly what I was looking for. Thanks! :)

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Answer 2

Jan 2013-3-16

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/67426-elegant-vectorized-way-of-getting-array-from-start_index-vector-and-end_index-vector#answer_78903

编辑：Jan 2013-3-16

在 MATLAB Online 中打开

start_index = [1 5 10];
end_index   = [3 8 12];
index(end_index + 1) = -1;  % Implicit pre-allocation
index(start_index)   = 1;
result               = find(cumsum(index));

In many cases logical indexing is more efficient:

result = (cumsum(index(1:end-1)) == 1);

An even more efficient method is FEX: mcolon.