How to count count number of times change occured

Question

Mekala balaji 2017-11-23

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/368842-how-to-count-count-number-of-times-change-occured

编辑： Mekala balaji 2017-11-27

Hi,
I have below time series data:
Time(sec) V1        V2
       0         1  
       0         1
       1         1
       1         1 
       1         1
       2         0
       2         0
       0         0
       0         1
      0         1
      0         0
      0         0
      0         0
      0         1 
      0         1
      0         1
      0         1
      0         1 
      0         0 
      0         0

Chage count:

when a variable current row value is different from previous row value, then count as 1 for a particular variable, and delta in the corresponding row. For example:

For variale1(V1):Compare the data in row3(in V1 column) is different from row2, I count it as 1 in row1 under V1 column and take the delta of (row3 &row2 values for V1 column, 1-0=1), same as row 6 value is different from row5,then count it as 2(under change count), and delta is (2-1)=1, so on~

Desired Output:
Time  V1(change count)  V1 (Delta)    V2(change Count)  V2 (Delta)
1        
2
3     1                 1
4
5
6     2                 1                 1             -1
7                                                          
8     3                -2
9                                         2              1
10 
11                                        3              -1
12
13
14                                        4               1
15
16
17
18
19                                        5              -1
20

Many thanks in advance~

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Answer 1

Adam 2017-11-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/368842-how-to-count-count-number-of-times-change-occured#answer_292804

编辑：Adam 2017-11-23

在 MATLAB Online 中打开

v1 = [0 0 1 1 1 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0]';
v1Delta = [0; diff( v1 )];
v1ChangeCount = v1Delta;
v1ChangeCount( v1Delta ~= 0 ) = 1:nnz( v1Delta );

I don't know what kind of structure your data is in, but that at least calculates the answer for e.g. v1 with 0s where there is no other number since you can't have empty space in a vector. You can replace them with Nans if you prefer.

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Mekala balaji 2017-11-27

编辑：Mekala balaji 2017-11-27

My data is array(double), because each data point is one second, I want to note after each change occurred how long the data is constant before next change occured. For example: In the above example you illustrated, the first change occured in 3rd row(at 3 seconds) and I want to know how many seconds before next chaged occured(next change here occured in 6th row) 6th second, and the data constant is for 3seconds(row3~row5), and so on for all the changes,

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