problem with matrix selection

Hi i want to clear some data from a matrix a of size 10*20. i have the index of data to clear. for a vector b we do it lik this: b(index)=[]

how to do it for matrix?

Answer 1

[Thomas]

You will have to clear a row or a column completely

to remove row

 a=[1 2 3;4 5 6; 7 8 9]
 a(2,:)=[]    % remove 2nd row

to remove column

 a=[1 2 3;4 5 6; 7 8 9]
 a(:,2)=[]  % remove 2nd column

otherwise you need to convert them to NaN if removing individually

a=[1 2 3;4 5 6; 7 8 9]
a(2,2)=NaN   % convert 2nd row 2nd col to NaN

[Rica]

thx