how to find the number of occurances

Question

johnson saldanha 2018-12-14

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/435680-how-to-find-the-number-of-occurances

编辑： madhan ravi 2018-12-14

采纳的回答： madhan ravi

i have a matrix x=[1 1 1 1 2 2 1 1 3 3 ]

i want the output to be x1=[1 2 1 3] and y1=[4 2 2 2]

x1 should have the reduced number from input and x2 should be the number of ocurances

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per isakson 2018-12-14

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Answer 1

madhan ravi 2018-12-14

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/435680-how-to-find-the-number-of-occurances#answer_352313

编辑：madhan ravi 2018-12-14

在 MATLAB Online 中打开

x=[1 1 1 1 2 2 1 1 3 3];
idx=logical([diff(x)~=0,1]);
x1=x(idx)
yy=find(idx);
yyy=diff(find(idx));
y1=[yy(1) yyy]
x2=histc(x,unique(x))  % number of occurences
unique_numbers_and_their_occurences=[unique(x); histc(x,unique(x))].' %bonus

Gives:

x1 =
     1     2     1     3
y1 =
     4     2     2     2
x2 =
     6     2     2
unique_numbers_and_their_occurences =
     1     6
     2     2
     3     2 

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johnson saldanha 2018-12-14

why are the number of columns of x1 and y1 not the same

madhan ravi 2018-12-14

编辑：madhan ravi 2018-12-14

在 MATLAB Online 中打开

Try this I corrected the mistake:

x=[1;1;1;1;2;2;1;1;3;3];
idx=logical([diff(x)~=0;1]);
x1=x(idx)
yy=find(idx);
yyy=diff(find(idx));
y1=[yy(1);yyy]
x2=histc(x,unique(x))  % number of occurences
unique_numbers_and_their_occurences=[unique(x) histc(x,unique(x))]

Gives :

>> COMMUNITY
x1 =
     1
     2
     1
     3
y1 =
     4
     2
     2
     2
x2 =
     6
     2
     2
unique_numbers_and_their_occurences =
     1     6
     2     2
     3     2
>> 