How to replace some Number in row matrix with NaN

Question

Yared Daniel 2021-6-15

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/856690-how-to-replace-some-number-in-row-matrix-with-nan

回答： Yared Daniel 2021-6-17

采纳的回答： Yared Daniel

在 MATLAB Online 中打开

I have a row vector like this

Y = [5 7 18 16 40 18 9 32 15 4 9 60 40 24 10 13];

What I want is to replace a number Y(i) with NaN if and only if its abs diff with Y(i-1) and Y(i+1) is greater than 10. if not the number remains as it was.

For instance abs(Y(4)-Y(5))=24 which is > 10 & abs(Y(5)-Y(6))=22 >10 therefore Y(5) = 40 has to be replaced with NaN

Y_new = [5 7 18 16 NaN 18 9 NaN NaN 4 9 NaN NaN Nan 10 13];

I have tried the follwing code and id didn't worked

clear 
clc
Y = [5 7 18 16 40 18 9 32 15 4 9 60 40 24 10 13];
len = numel(Y);
A=Y;
start = 1;
for jj = 2 :len -1
    if abs(Y(start)- Y(jj))<10 
        start=jj;
    elseif abs(Y(start)- Y(jj))>10 && abs(Y(jj)- Y(jj+1))<10 
         Y(start)=NaN;
         start = jj+1;
    elseif abs(Y(start)- Y(jj))>10 && abs(Y(jj)- Y(jj+1))>10
        Y(jj) = NaN;
         start = jj+1;
    else
    end
end

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Answer 1

Yared Daniel 2021-6-17

0
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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/856690-how-to-replace-some-number-in-row-matrix-with-nan#answer_726760

I have solved it!

clear

Y = [5 7 18 16 40 18 9 32 15 4 9 60 40 24 10 13];

idx = find(abs(diff(Y))>10);

L = numel(idx);

Y_new=Y;

for i=1:L-1

if abs(idx(i)-idx(i+1))==1

Y_new(idx(i)+1) =NaN;

else

end

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Answer 2

KSSV 2021-6-15

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/856690-how-to-replace-some-number-in-row-matrix-with-nan#answer_725230

在 MATLAB Online 中打开

 
Y = [5 7 18 16 40 18 9 32 15 4 9 60 40 24 10 13];
Y_new = [5 7 18 16 NaN 18 9 NaN NaN 4 9 NaN NaN NaN 10 13];
dY = diff([0 Y]) ;
idx = dY>10 ;
Y1 = Y ; 
Y1(idx) = NaN ;