# Removing a Range of Elements from an array

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Hans123 on 28 Mar 2019
Commented: Hans123 on 28 Mar 2019
Hi,
I have a matrix M and I am interested in the 12th column which has elements [1 2 3 4..... 540 589 760 761 770 47 46 47 48]
My goal is to get rid of all the elements after 750, including the values less than it.
My first code was
M(M(:,12)>750,:) =[];
but this didn't get rid of 47 46 48..
Mx= find(M(:,12)>750);
Mxmin=min(Mx); %to find the smallest value above 750 (in this case 760)
M(Mxmin:end,12)= [];
currently I am using this code, which gives me an error that says A null assignment can have only one non-colon index.
What am I doing wrong?
Hans123 on 28 Mar 2019
I want to eliminate the whole row of that matrix, if the column 12 contains a 760 - I want that row removed. That's why I used [ ]

Walter Roberson on 28 Mar 2019
M(find(M:,12)>750,1):end, :) = [];
Hans123 on 28 Mar 2019
wow!
Thank you, really appreciate it

Jos (10584) on 28 Mar 2019
ix = find(M(:,12) > 750, 1, 'first') % find the row index of the first element in the 12th column of A being larger than 750
M(ix:end,:) = [] % remove all the rows of M starting with this row