How to remove duplicate rows in a matrix by considering the repeated values in a specific column?

97 次查看（过去 30 天）
Gayan Lankeshwara
Gayan Lankeshwara 2019-10-23
评论： Zach Williams 2021-4-23
%% consider the following example.
A = [1 2 4; 3 5 7;1 5 8; 2 9 4]
In matrix A, column 1 has a duplicate value which is 1. I need to keep the first met value and remove the rest accordingly. At the same time, the indices of non-duplicates should not be changed.
The possible solution should be,
A_without_dup = [1 2 4;3 5 7;2 9 4]
%% only the final row is removed because a duplicate is found in that row based on the value of column 1 in A.
Thanks.

请先登录，再回答此问题。

采纳的回答

Mohammad Sami
Mohammad Sami 2019-11-1
You can use the unique function to return you the index of the unique values in the first column.
Use the stable keyword so the order is preserved. You can then use the index to keep the unique rows.
[~,uidx] = unique(A(:,1),'stable');
A_without_dup = A(uidx,:);
  3 个评论
显示 1更早的评论
David Linsenbardt
David Linsenbardt 2021-1-12
You can also combine rows w/ stable and remove rows where duplicates exist in multiple columns:
[~,uidx] = unique(data(:,[1 2]),'rows','stable');
data = data(uidx,:);

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

标签

产品


版本

R2019a

Community Treasure Hunt

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

Start Hunting!

Translated by