Filter löschen
Filter löschen

how to delete repeated rows in a table?

6 Ansichten (letzte 30 Tage)
Jayden Yeo
Jayden Yeo am 24 Sep. 2021
Kommentiert: Jayden Yeo am 27 Sep. 2021
I have an array M below. There are some repeated values in column 1. I would like to write a code that deletes all the rows that have repeated values in column 1. The final answer should be [518640 5.959; 522225 8.988].
This is a sample dataset. My actual data has more than 50,000 rows, and I need to delete all the repeated data. Thanks.
M = [518460 3.322; 518460 -12.984; 518520 3.798; 518520 -10.28; 518580 7.763; 518580 16.851; 518640 5.959; 522225 8.988];

Akzeptierte Antwort

per isakson
per isakson am 24 Sep. 2021
Bearbeitet: per isakson am 27 Sep. 2021
Test this
%%
M = [518460 3.322; 518460 -12.984; 518520 3.798; 518520 -10.28; 518580 7.763; 518580 16.851; 518640 5.959; 522225 8.988];
%%
[~,ixu] = unique( M(:,1), 'stable' );
M(ixu,:)
ans = 5×2
1.0e+05 * 5.1846 0.0000 5.1852 0.0000 5.1858 0.0001 5.1864 0.0001 5.2222 0.0001
In response to comment
If everything fails, try a for-loop
for jj = 1 : size(M,1)
ixm = find( M(jj,1) == M(:,1) );
if numel(ixm) >= 2
M(ixm,1) = nan;
end
end
M( isnan(M(:,1)), : ) = []
M = 2×2
1.0e+05 * 5.1864 0.0001 5.2222 0.0001
  3 Kommentare
per isakson
per isakson am 27 Sep. 2021
See response in the answer.
Jayden Yeo
Jayden Yeo am 27 Sep. 2021
Thanks a lot.

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (1)

Walter Roberson
Walter Roberson am 27 Sep. 2021
format long g
M = [518460 3.322; 518460 -12.984; 518520 3.798; 518520 -10.28; 518580 7.763; 518580 16.851; 518640 5.959; 522225 8.988]
M = 8×2
1.0e+05 * 5.1846 0.0000 5.1846 -0.0001 5.1852 0.0000 5.1852 -0.0001 5.1858 0.0001 5.1858 0.0002 5.1864 0.0001 5.2222 0.0001
[~, ia] = unique(M(:,1), 'stable');
M = M(ia,:)
M = 5×2
1.0e+05 * 5.1846 0.0000 5.1852 0.0000 5.1858 0.0001 5.1864 0.0001 5.2222 0.0001

Tags

Produkte


Version

R2015b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by