delete element from vector

6,463 views (last 30 days)
Majid Al-Sirafi on 24 Sep 2012
Hi everyone
how can I delete element from vector .... for example
a=[1,2,3,4,5]
how can I delete 3 from above vector to be
a=[1,2,4,5]
thank you
majid
Jeffrey Houston on 4 Jan 2021
Hi Hamna, sorry for the late response, but I'll answer for others anyways. The line of code below will do the trick for what you're asking for.
b = a(3)

Daniel Shub on 24 Sep 2012
Edited: MathWorks Support Team on 9 Nov 2018
I can think of three ways that are all slightly different
a=[1,2,3,4,5];
If you want to get rid of all cases where a is exactly equal to 3
b = a(a~=3);
If you want to delete the third element
b = a;
b(3) = [];
or on a single line
b = a([1:2, 4:end]);
Or, as Jan suggests:
a = [2,3,1,5,4]
a(a == 3) = []
Rik on 31 Mar 2021
@Anthony Dave Flags are not for personal bookmarks. Please remove your flag.

Jan on 24 Sep 2012
Edited: Jan on 24 Sep 2012
a = [1,2,3,4,5]
a(3) = []
Or:
a = [2,3,1,5,4]
a(a == 3) = []
These methods are explained exhaustively in the "Getting Started" chapters of the documentation. It is strongly recommended to read them completely. The forum is not though to explain the fundamental basics. Thanks.
Joel Bay on 28 Jun 2019
"These methods are explained exhaustively in the "Getting Started" chapters of the documentation."
Wrong, definetely not exhaustively after comparing Daniel's answer and the documentation. Logical indexing is not even mentioned. The answers to this question is still useful in 2019.

Andrei Bobrov on 24 Sep 2012
a = a(abs(a - 3) > eps(100))
Majid Al-Sirafi on 24 Sep 2012
than you very much

Elias Gule on 1 Dec 2015
% Use logical indexing
a = a(a~=3)
Ntsakisi Kanyana on 31 Mar 2020
Does it work on strings?

masoud sistaninejad on 23 Aug 2021 at 23:06
A = [ 1 2 3 4 5 6 7]
A = 1×7
1 2 3 4 5 6 7
B = [1 3 6]
B = 1×3
1 3 6
C = setdiff(A,B)
C = 1×4
2 4 5 7