loop indexing length of non zeroes

Question

Morten Jørgensen 2019-6-2

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https://ww2.mathworks.cn/matlabcentral/answers/465173-loop-indexing-length-of-non-zeroes

编辑： Adam Danz 2019-6-10

Hi, I'm trying to make a loop that finds the length of a sequence of numbers:

I want to find when x(:,4) is not equal to zero, and then find how long it's is the same number, I want to save the number and the start row, and the end row.

my output should look something like this:

Id    start    end    length
10    1320    1331    11
9     1352    1354    3

thanks for any help

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Morten Jørgensen 2019-6-3

thanks a lot

Is it possible to igore when there i zero?

Adam Danz 2019-6-5

编辑：Adam Danz 2019-6-10

Have you tried the answer I proposed below? It ignores 0s as you described.

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Answer 1

Adam Danz 2019-6-3

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https://ww2.mathworks.cn/matlabcentral/answers/465173-loop-indexing-length-of-non-zeroes#answer_377643

编辑：Adam Danz 2019-6-4

在 MATLAB Online 中打开

Here are the steps needed to build your table.

% Create fake data that looks like your example
x = rand(2000,5);
x(:,4) = 0;
x(1320:1331,4) = 10;
x(1352:1354,4) = 9;
% calculate table components
isZero = x(:,4)==0;
dz = [0;diff(isZero)];
start = find(dz == -1);         %start column 
endIdx = find(dz == 1)-1;       %end column
ID = x(start,4);                %ID column
len = endIdx - start;           %Length column
% Create table
T = table(ID,start,endIdx,len,'VariableNames', {'Id','start','endIdx','length'});

Result

T =
  2×4 table
    Id    start    endIdx    length
    __    _____    ______    ______
    10    1320      1331       11  
     9    1352      1354        2  
    