Filter löschen
Filter löschen

How to delete all rows of an array that have a specified number in a particular column?

1 Ansicht (letzte 30 Tage)
How can you delete a row of an array if the number in a particular column doesn't equal a specified number or even multiple numbers? For example, let A = magic(5). How can we delete any row where A(2,:) = 5? B=A(A(:,2)~=5) doesn't quite do it, only gives me the first column. In this case, there's only one row, but I'm looking for a general solution.

Akzeptierte Antwort

Walter Roberson
Walter Roberson am 30 Mär. 2022
A(:, A(2,:) == 5) = [];
  2 Kommentare
L'O.G.
L'O.G. am 30 Mär. 2022
Bearbeitet: L'O.G. am 30 Mär. 2022
@Walter Roberson Thanks, but that removes the column with that value, not the row. I realized (thanks to you!) that this is what I want: A(A(2,:) == 5,:) = [];
Walter Roberson
Walter Roberson am 30 Mär. 2022
How can we delete any row where A(2,:) = 5
A(2,:) is a query about contents of row 2, not about a particular column. It does not make sense to ask about removing rows for which something is true about row 2.
If you want to deal with columns, then
A = magic(5)
A = 5×5
17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9
A(A(:,2) == 5, :) = []
A = 4×5
17 24 1 8 15 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Kategorien

Mehr zu Matrix Indexing finden Sie in Help Center und File Exchange

Produkte


Version

R2021b

Community Treasure Hunt

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

Start Hunting!

Translated by