select rows satisfying a particular condition

Question

Elysi Cochin 2019-4-25

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/458453-select-rows-satisfying-a-particular-condition

编辑： Alex Mcaulley 2019-4-25

采纳的回答： Andrei Bobrov

在 MATLAB Online 中打开

having a matrix of dim 5 x 10

if i give start_index = 1, and end_index = 3, i wanted to get rows starting with value of start_index and ending with end_index excluding zeros.

eg: rows 4 and 5

 cell_matrix = {[1  2  3] 
 [1  3] }

saved to a cell matrix

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Answer 1

Andrei Bobrov 2019-4-25

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/458453-select-rows-satisfying-a-particular-condition#answer_372227

% Let A - your array.
[ii,jj,v] = find(A);
z = [ii,jj,v];
z = sortrows(z,[1,2]);
out = accumarray(z(:,1),z(:,3),[],@(x){fun(x,1,3)});
function out = fun(x,b,e)
    x = x(:)';
    out = [];
    if isequal(x([1,end]) , [b,e]) && all(diff(x(:)) > 0)
        out = x;
    end
end

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Answer 2

Alex Mcaulley 2019-4-25

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/458453-select-rows-satisfying-a-particular-condition#answer_372229

编辑：Alex Mcaulley 2019-4-25

在 MATLAB Online 中打开

a = randi([0,2],5,10);
start_index = 1;
end_index = 3;
b = mat2cell(a(start_index:end_index,:),ones(1,end_index-start_index+1),size(a,2));
b = cellfun(@(x) myfun(x),b,'UniformOutput',false);
function x = myfun(x)
    x(x==0) = [];
end