Delete only consecutive repeated string entries from a dataset in matlab
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hi!
I am relatively new to matlab. I have a dataset having three columns, time, pitch and notation. for eg
time pitch notation
2.5725 329.63 G
2.5800 329.63 G
2.5900 311.13 M
2.5900 311.13 M
2.6000 570.40 P
I want to remove duplicates occurring consecutively in the file such that the order remains the same. so the output will be:
time pitch notation
2.5725 329.63 G
2.5900 311.13 M
2.6000 570.40 P
I am currently using matlab 7.9.0 so the first of unique command id not supported. Can anyone tell me how to go about it further.
[EDITED, table formatted, Jan]
5 Comments
Jan
on 30 Aug 2013
Edited: Jan
on 30 Aug 2013
I still do not understand the empty lines and the type of the input is not explained here. Is this a text file, a cell containing strings, or or is pitch a field of a struct, which contains a double vector?
What should happen for:
2.5725 329.63 GM
2.5800 329.63 GM
2.5725 329.63 GM
2.5800 329.63 GM
So does "consecutively" mean the position in the array or should a line vanish, if there is any equal set of values before, even if other lines appear in between?
I assume that the solution is very easy, if you define the wanted procedure and the class of the input exactly.
Accepted Answer
Andrei Bobrov
on 29 Aug 2013
Edited: Andrei Bobrov
on 30 Aug 2013
C ={ 'time' 'pitch' 'notation'
2.5725 329.63 'GM'
2.5800 329.63 'GM'
2.5900 311.13 'MM'
2.6000 570.40 'PM'
2.6725 329.63 'GM'
2.6800 329.63 'GM'
2.7900 311.13 'MM'
2.8900 311.13 'MM'
2.9000 570.40 'PM'
2.9500 570.40 'PM'
3.1000 570.40 'PM'};
d = cell2dataset(C); % your dataset - array
[~,~,ii] = unique(d.notation);
out = d([true;diff(ii)~=0],:);
ADD without dataset array
C ={ 'time' 'pitch' 'notation'
2.5725 329.63 'GM'
2.5800 329.63 'GM'
2.5900 311.13 'MM'
2.6000 570.40 'PM'
2.6725 329.63 'GM'
2.6800 329.63 'GM'
2.7900 311.13 'MM'
2.8900 311.13 'MM'
2.9000 570.40 'PM'
2.9500 570.40 'PM'
3.1000 570.40 'PM'};
[ii,ii,ii] = unique(C(2:end,3));
out = C([true(2,1);diff(ii)~=0],:);
ADD 2
scale = {'GM';'PM'};
[~,ii] = ismember(C(2:end,3),scale);
i1 = ii > 0;
C1 = C(i1,:);
out = C1([true(2,1);diff(ii(i1))~=0],:);
6 Comments
More Answers (1)
Simon
on 29 Aug 2013
Hi!
I don't understand why the second entry is removed. Is a "duplicate" defined if all three columns match or only the second and third?
Does the unique command in 7.9 support rows? Like
b = unique(A, 'rows')
Does your data set consist of single lines for each entry? You could try to put each data set as a string in a cell array and use unique of the cell array.
3 Comments
Simon
on 29 Aug 2013
Hi!
Try it with a cell array of strings, as proposed.
The unique command has additional return values that contain the relation between the sorted output and the input. Check the documentation for more information.
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