Delete row from Matrix

461 次查看(过去 30 天)
Nancy
Nancy 2012-6-21
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.
  3 个评论
Yuvraj Praveen Soni
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

请先登录,再进行评论。

采纳的回答

Jan
Jan 2012-6-22
编辑:MathWorks Support Team 2018-11-9
If you have a matrix A and want to delete the 3rd and 9th rows, you can use the command:
A([3,9],:) = [];
  5 个评论
Walter Roberson
Walter Roberson 2019-6-18
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
Arezoo Samiei 2021-10-7
Thank you so much Jan!

请先登录,再进行评论。

更多回答(6 个)

Peter
Peter 2012-11-30
"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

Dan W
Dan W 2015-1-23
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 个评论
Andrei Bobrov
Andrei Bobrov 2016-6-10
Hi Mehul! It new question.
Andrei Bobrov
Andrei Bobrov 2016-6-10
out = m1;
out(m2,:) = [];

请先登录,再进行评论。


Andrei Bobrov
Andrei Bobrov 2012-6-21
m = m(setdiff(1:size(m,1),[3,9]),:);
  5 个评论
Jan
Jan 2012-6-22
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
pradeep kumar 2014-8-30
@ 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]

请先登录,再进行评论。


Alireza Rezvani
Alireza Rezvani 2016-6-19
sry, how i can Deleting individual columns of a matrix, any body know?
  2 个评论
Muhammad Usman Saleem
Assume out is your matrix and you want to delete its first column, try this code,
out(:,1) = [];
surendra bala
surendra bala 2018-3-31
Yes. This is the easiest way you can do.

请先登录,再进行评论。


zshockz
zshockz 2016-10-10
So I have to make a function that is able to delete a row in a matrix [I have 3 by 3]. I am not sure how to do this, please leave any help you can!

LISSA DUVVU
LISSA DUVVU 2018-9-29
i want to delete all columns data where the 4th row contains number 7
  1 个评论
Jan
Jan 2018-10-7
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.

请先登录,再进行评论。

类别

Help CenterFile Exchange 中查找有关 Logical 的更多信息

Community Treasure Hunt

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

Start Hunting!

Translated by