Find a series of consecutive numbers and change index of them

조회 수: 2 (최근 30일)
Jaehwi Bong
Jaehwi Bong 2019년 8월 12일
답변: Andrei Bobrov 2019년 8월 12일
Hi,
I have this kind of data. The first column and second column of the data refers to Index and time series(not consecutive) relatively.
Data = [1 1; 1 2; 1 3; 1 5; 1 6; 1 10; 1 11; 1 13; 1 20; 1 21; 1 22;];
I'd like to change this index number using Matlab code(to apply to thousands of data) when the value of the second colmn is not consecutive numbers.
So in my example, the first column should be changed [1; 1; 1; 2; 2; 3; 3; 4; 5; 5; 5;] .
If anyone can help, it would be greatly appreciated.
Thank you!

채택된 답변

the cyclist
the cyclist 2019년 8월 12일
편집: the cyclist 2019년 8월 12일
Data(:,1) = cumsum(diff([Data(1,2); Data(:,2)]) ~= 1);
will change the first column to what you want.
That's might be a bit "obfuscated" for you, but it is pretty straightforward to parse what is going on.
[Data(1,2); Data(:,2)]
is appending another copy of the first element at the front of the vector. I do that so that the first element of your vector will look non-consecutive to the "prior" one, and therefore be assigned index 1.
diff() ~= 1
is identifying the locations with non-consecutive jumps, putting a 1 there.
cumsum()
takes the cumulative sum along the vector, which means that each time a 1 is encountered, your index is incremented.

추가 답변 (1개)

Andrei Bobrov
Andrei Bobrov 2019년 8월 12일
[~,~,Data(:,1)] = unique(cumsum(Data(:,1)) - Data(:,2),'stable');

카테고리

Help CenterFile Exchange에서 Data Type Conversion에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by