How can I delete the rows of a matrix in matlab under a given condition
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Hello everybody,
I have a matrix which has 10118 rows and 14 columns. I would like to delete the number of rows having values greater than 100. How can I do this?
Thanks in advance!
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Accepted Answer
madhan ravi
on 14 Nov 2018
Edited: madhan ravi
on 23 Nov 2018
EDITED
%Numbers greater than 100
idx = matrix > 100;
matrix ( ~ ( sum ( idx , 2) == 0 ) , : ) = []
%__________________________
%Numbers lesser than 100
idx = matrix < 100;
matrix ( sum ( idx , 2 ) ~= 0 , : ) = []
21 Comments
Stephen23
on 23 Nov 2018
Edited: Stephen23
on 23 Nov 2018
This code, although convoluted, will remove rows with any value greater than 100:
idx = matrix < 100;
matrix ( ~ ( sum ( idx , 2) == 0 ) , : ) = []
But what is this going to do?:
idx = matrix < 100;
matrix ( sum ( idx , 2 ) == size ( matrix , 2 ) , : ) = []
madhan ravi
on 23 Nov 2018
Edited: madhan ravi
on 23 Nov 2018
@Skyscraper: yes because if any of the numbers in a matrix is less than 100 the whole row is removed, the matrix which you gave contains numbers less than 100 in each row.
More Answers (1)
Stephen23
on 23 Nov 2018
Edited: Stephen23
on 23 Nov 2018
>> A = [110,0,10,70,15;100,30,50,20,9;50,-150,95,65,7]
A =
110 0 10 70 15
100 30 50 20 9
50 -150 95 65 7
>> B = A(~any(abs(A)>100,2),:) % create a new array B,
B =
100 30 50 20 9
>> A(any(abs(A)>100,2),:) = [] % or delete rows from A.
A =
100 30 50 20 9
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