Synchronise data starting from a fixed threshold

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Giuseppe 2018-7-31

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/412915-synchronise-data-starting-from-a-fixed-threshold

评论： Giuseppe 2018-8-4

Hello guys,

I'm trying to figure out how to manipulate a matrix to synchronise data of each column based on a given threshold. Below an example of the matrix (12x4). I need to obtain the same matrix but only with values > 1 for a lenght of 5 points (5x4). Generally my data will alwasy have a threshold > 1 and I will always be able to determine a given number of points such as final length will be the same in the end. Columns however may vary, in this case only 4.

I tried some for loop options discussed in another thread but without finding a real solution. I have got stuck.

773487342198182  0.600138756438417  0.772170734960123  0.516639735856335
864087340442978  0.615542221162260  0.869415217974424  0.537233561755918
991682274100864  0.638389426741996  0.982410980592013  0.615436818611677
32088921825082  0.706869092358629  1.09369088583133  0.757585637236141
28357938862586  0.907713092310730  1.26556377855575  1.00404112351146
90532643030186  1.43660651296947  1.90422770765619  1.55522956023284
4072812534284  2.77316107773783  4.37097547909669  3.09343285415927
1009031962690  6.15011521861756  12.1192439504818  7.51757113064298
2552255198974  14.5139540875845  32.2458223148952  19.2312119978824
068671806419  33.8800895937913  76.5865546546643  46.6144406361416
680987120115  74.3217216672375  160.666680053232  102.442449362564
947876642696  149.265403348143  298.912052552757  201.592183165793

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jonas 2018-7-31

I do not understand. Give an example of input and output of a single column.

Giuseppe 2018-7-31

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Input is above in the original message. I would expect this outcome (example first column starting from the first value >1 with length equal 5 points):

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Answer 1

jonas 2018-7-31

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/412915-synchronise-data-starting-from-a-fixed-threshold#answer_331101

编辑：jonas 2018-8-1

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With the data given in the comment to this answer, try this script:

A=readtable('data.csv');
A=table2array(A)
A(A<1)=NaN;
A=mat2cell(A,size(A,1),ones(1,size(A,2)))
A=cellfun(@(x)x(~isnan(x)),A,'uniformoutput',false)
A=cellfun(@(x)x(1:5),A,'uniformoutput',false)
out=cell2mat(A)

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jonas 2018-8-3

编辑：jonas 2018-8-3

在 MATLAB Online 中打开

Next iteration. I will allow one for-loop this time :)

A=readtable('data.csv');
A=table2array(A);
A=mat2cell(A,size(A,1),ones(1,size(A,2)))
for i=1:length(A)
    A{i}(1:find(A{i}>=1,1,'first'))=NaN;
end
A=cellfun(@(x)x(~isnan(x)),A,'uniformoutput',false)
A=cellfun(@(x)x(1:5),A,'uniformoutput',false)
out=cell2mat(A)

The difference here is that the loop only removes data up until the first '1'. This means that you can now end up with values less than one in your output, granted that they appear shortly after the first one.

Giuseppe 2018-8-4