Removing elements from matrix

Question

Marin 2012-5-14

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38303-removing-elements-from-matrix

评论： Julia 2014-8-5

Hi everyone,

I was wonderning is there an easy way to remove some of the elemetts from matrix. I have a data array data(300x2) and I want to remove all rows that have the value in the second column smaller than 0.18.

I tried something like

data=data(data(:,2)<0.18);

and similar combinations but it doesn't work.

Thank you in advance for any advice you can offer.

2 个评论
显示无隐藏无

harsha 2014-8-5

hi

i have a 49x49 matrix and i want to delete the single element at center of the matrix.how can i do so?please help.

Julia 2014-8-5

What do you mean with delete? Set to 0? You can delete the row or the column containing the element, but you cannot create a hole in the middle of the matrix.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Andrei Bobrov 2012-5-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38303-removing-elements-from-matrix#answer_47740

在 MATLAB Online 中打开

data=data(data(:,2)>=0.18,:);

ADDED after Marin's comment

simple example

data1 =[...
   3
   8
   3
   6
   7]
data2 =[...
   2
   2
   3]
data1(ismember(data1(:),data2(:))) = nan

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Marin 2012-5-14

yeah, of course, now I see I could have solved it myself, but I've been too hasty. :)

thank you very much :)

another thing, if you can help me also.

if I have two data sets data1(300x2) and data2(50x2) and data2 contains elements that are in data1 (of course not all of them).

how do I create a matrix which has the data that is in data1 and not in data2 ?

请先登录，再进行评论。

Answer 2

Marin 2012-5-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38303-removing-elements-from-matrix#answer_47844

Excellent. Thank you!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。