remove first value that appears after sequence of NaNs

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MatLab Code N 2020-6-27

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/555895-remove-first-value-that-appears-after-sequence-of-nans

评论： Star Strider 2020-6-29

example_data.xlsx

Hi,

In my dataset, the first value that appears after a sequence of NaNs needs be removed. This removed value also need to be made NaN so that I dont consider in further anlaysis. I have attached the example dataset for your reference, I have colored some of those value to be removed in red.

I highly appreciate your help.

Thanks!

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madhan ravi 2020-6-27

A short example would help.

MatLab Code N 2020-6-27

I have attached the excel file with example dataset

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Answer 1

Star Strider 2020-6-28

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/555895-remove-first-value-that-appears-after-sequence-of-nans#answer_458110

在 MATLAB Online 中打开

Try this:

D = readmatrix('example_data.xlsx');
R01 = strfind(isnan(D(:,1)).', [1 0]);                  % Find Indices Of [0 1] Transitions
Out = D;                                                % Duplicate Original Matrix In 'Out'
Out(R01+1,:) = NaN;                                     % Replace Appropriate Values With 'NaN'

This appears to do what you want on the rows that I checked. It assumes that the NaN values are the same rows in both columns, since they appear to be in the posted file. The ‘Out’ matrix is the output of the code.

.