# Delete row from Matrix

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Nancy on 21 Jun 2012
Commented: muhammad usama on 7 May 2023
I have a Matrix of 400 rows and 40 columns. I want to completely remove rows 3 and 9 to get a matrix with 398 rows. How can I do it in MATLAB.
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Yuvraj Praveen Soni on 9 Dec 2019
if assume A is your matrix with 400 rows and 40 column,
To remove 3rd row
a(3,:)=[];
now your 9th row become 8th row;
a(8,:)=[];
and with this your 3rd and 9th row will be deleted, you can also check the size by
size(a);
Thank You
Gokul Krishna N on 2 Nov 2020
Thanks

Jan on 22 Jun 2012
Edited: MathWorks Support Team on 9 Nov 2018
If you have a matrix A and want to delete the 3rd and 9th rows, you can use the command:
A([3,9],:) = [];
Walter Roberson on 18 Jun 2019
Katarina, I am not clear as to where you are seeing anything about deleting columns in this Answer?
If you want to delete a column then name it in the second index:
A(:,k) = [];
Arezoo Samiei on 7 Oct 2021
Thank you so much Jan!

Peter on 30 Nov 2012
"I have a Matrix of 400 rows and 40 columns.I want to completely remove rows 3 and 9 to get a matrix with 398 rows. How can I do it in MATLAB."
Matrix_2 = Matrix_1( [1:2,4:8,10:end] , : )
Best,
Pete
muhammad usama on 7 May 2023
Thank you, the simplest one.

Dan W on 23 Jan 2015
I'm not sure if this is new syntax or not, but it works with R2012a and it's fast and simple.
x = rand(100);
tic;
x([3,9],:) = [];
toc; % Elapsed time is 0.000230 seconds.
##### 3 CommentsShow 1 older commentHide 1 older comment
Andrei Bobrov on 10 Jun 2016
Hi Mehul! It new question.
Andrei Bobrov on 10 Jun 2016
out = m1;
out(m2,:) = [];

Andrei Bobrov on 21 Jun 2012
m = m(setdiff(1:size(m,1),[3,9]),:);
Jan on 22 Jun 2012
SETDIFF has a remarkable overhead. ISMEMBER is smarter and twice as fast for a 100x100 matrix:
m = m(~ismember(1:size(m, 1), [3,9]), :);
pradeep kumar on 30 Aug 2014
@ Andrei Bobrov , @ Walter Roberson,@ Jan Simson . how delete a particular row and column of a matrix by using "setdiff" . Say m= [1 2 3 4 ; 5 6 7 8; 9 10 11 12 ; 13 14 15 16 ]. i want to delete 1st row and 2nd column to obtain m=[5 7 8; 9 11 12;13 15 16]

Alireza Rezvani on 19 Jun 2016
sry, how i can Deleting individual columns of a matrix, any body know?
Muhammad Usman Saleem on 19 Jun 2016
Assume out is your matrix and you want to delete its first column, try this code,
out(:,1) = [];
surendra bala on 31 Mar 2018
Yes. This is the easiest way you can do.

LISSA DUVVU on 29 Sep 2018
i want to delete all columns data where the 4th row contains number 7
Jan on 7 Oct 2018
Please do not attach a new (and very vague) question in the section for answers of another questions. Such thread-hijacking is confusing only, because it is not longer clear, to which question an answer belong. Please open your own question and delete this pseudo-answer. Thanks.