How get row index of first and last appearance each unique cell element
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Hi,
I have below cell array, and I want to get the unique elements based on 2nd column.
MUY09KT00 TW00.00
MUY09KT00 TW00.00
MUY09KT00 TW00.00
MHJ09KT00 PW00.00
MHJ09KT00 PW00.00
LHJ09KT00 NPW00.00
LHJ09KT00 NPW00.00
LHJ09KT00 NPW00.00
in this case, the unique element first index are:
1
4
6
in this case, the unique element last index are:
3
5
8
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Accepted Answer
Bruno Luong
on 12 Oct 2018
Edited: Bruno Luong
on 12 Oct 2018
Make the output in the "stable" order:
x = ["MUY09KT00" "TW00.00"
"MUY09KT00" "TW00.00"
"MUY09KT00" "TW00.00"
"MHJ09KT00" "PW00.00"
"MHJ09KT00" "PW00.00"
"LHJ09KT00" "NPW00.00"
"LHJ09KT00" "NPW00.00"
"LHJ09KT00" "NPW00.00"]
[~,~,J] = unique(x(:,2)); % Based on the 2nd column
jump = find([true; diff(J); true]);
first = jump(1:end-1)
last = jump(2:end)-1
first =
1
4
6
last =
3
5
8
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More Answers (1)
Sean de Wolski
on 12 Oct 2018
Unique is your friend:
x = ["MUY09KT00" "TW00.00"
"MUY09KT00" "TW00.00"
"MUY09KT00" "TW00.00"
"MHJ09KT00" "PW00.00"
"MHJ09KT00" "PW00.00"
"LHJ09KT00" "NPW00.00"
"LHJ09KT00" "NPW00.00"
"LHJ09KT00" "NPW00.00"]
[~,first] = unique(x(:,1), 'first')
[~,last] = unique(x(:,1), 'last')
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