delete rows depend on repeated value from 1 col

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Hi I have a 20000x60 cell matrix I want to delete rows depend on repeated values from the first columns.
s = {
1 '2013-10-01' '05:35:00' '01:05:00'
2 '2013-10-01' '10:20:00' '00:00:00'
2 '2013-10-01' '10:20:00' '00:00:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
5 '2013-10-01' '14:50:00' '00:50:00'
5 '2013-10-01' '14:50:00' '00:50:00'
6 '2013-10-01' '15:15:00' '01:15:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'}
the result should like:
s1 =
1 '2013-10-01' '05:35:00' '01:05:00'
2 '2013-10-01' '10:20:00' '00:00:00'
3 '2013-10-01' '11:00:00' '00:40:00'
5 '2013-10-01' '14:50:00' '00:50:00'
6 '2013-10-01' '15:15:00' '01:15:00'
7 '2013-10-01' '15:55:00' '00:05:00'
8 '2013-10-01' '19:00:00' '00:05:00'
9 '2013-10-01' '19:10:00' '00:10:00'
I use unique for it but because the different type of data there is Error using cell/unique (line 85) Input A must be a cell array of strings."

Accepted Answer

Star Strider
Star Strider on 16 Feb 2016
If the number in the first column is the same for all repeated values in the rest of the row, just use it.
Using your example data:
s = { 1 '2013-10-01' '05:35:00' '01:05:00'
2 '2013-10-01' '10:20:00' '00:00:00'
2 '2013-10-01' '10:20:00' '00:00:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
3 '2013-10-01' '11:00:00' '00:40:00'
5 '2013-10-01' '14:50:00' '00:50:00'
5 '2013-10-01' '14:50:00' '00:50:00'
6 '2013-10-01' '15:15:00' '01:15:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'
7 '2013-10-01' '15:55:00' '00:05:00'};
sc1 = cellfun(@(x)num2str(x, '%.0f'), s(:,1));
[s1u, ia] = unique(sc1);
s1 = s(ia,:)
s1 =
[1.0000e+000] '2013-10-01' '05:35:00' '01:05:00'
[2.0000e+000] '2013-10-01' '10:20:00' '00:00:00'
[3.0000e+000] '2013-10-01' '11:00:00' '00:40:00'
[5.0000e+000] '2013-10-01' '14:50:00' '00:50:00'
[6.0000e+000] '2013-10-01' '15:15:00' '01:15:00'
[7.0000e+000] '2013-10-01' '15:55:00' '00:05:00'
You may have to modify this slightly if your actual cell array is different, but it works with the array you posted, and as I interpreted it.
  8 Comments

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More Answers (1)

MHN
MHN on 16 Feb 2016
Edited: MHN on 16 Feb 2016
Consider this example (it is not the fastest and easiest way, but it solves your problem)
s = {3 '2013-10-01' '11:00:00' '00:40:00'; 3 '2013-10-01' '11:00:00' '00:40:00'; 3 '2013-10-01' '11:00:00' '00:40:00'; 5 '2013-10-01' '14:50:00' '00:50:00'; 5 '2013-10-01' '14:50:00' '00:50:00'; 6 '2013-10-01' '15:15:00' '01:15:00'; 7 '2013-10-01' '15:55:00' '00:05:00'};
col1 = cell2mat(s(:,1));
uniqcol1 = union(col1,col1);
% change all the repeated rows to '0' (or some number which is unused in the first column) except the first one and then remove them.
for i=1:length(uniqcol1)
for j = 1:size(s,1)
if uniqcol1(i)==s{j,1}
for k = j+1: size(s,1)
if uniqcol1(i)==s{k,1}
s{k,1} = 0;
end
end
end
end
end
col1 = cell2mat(s(:,1));
s(col1==0,:)=[];
  1 Comment
bero
bero on 17 Feb 2016
It is so slowly for my my big matrix, I need more efficient and faster process...

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