Removing elements from matrix

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.

[harsha]

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]

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.

Answer 1

[Andrei Bobrov]

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

ADDED after Marin's comment

simple example

data1 =[...
2     3
5     8
10     3
4     6
6     7]

data2 =[...
9     2
10     2
6     3]

data1(ismember(data1(:),data2(:))) = nan

[Marin]

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 ?

Answer 2

[Marin]

Excellent. Thank you!